diff --git a/src/components/map-projects/MapProject.jsx b/src/components/map-projects/MapProject.jsx
index 3f92f9c..851fc6e 100644
--- a/src/components/map-projects/MapProject.jsx
+++ b/src/components/map-projects/MapProject.jsx
@@ -124,7 +124,7 @@ import { createLookupSession, LOOKUP_NOT_FOUND } from './lookupSession'
 import { parseConceptKey } from './conceptKey'
 import { normalizeLookupConfig } from './lookupConfigFields'
 import { getDeclaredLocales, getDefaultTargetRepoVersion, getProjectTargetRepoVersion, getSavedTargetRepoVersion, getTargetRepoVersionFromUrl, getTargetRepoVersionId } from './projectTargetRepo'
-import { buildBridgeTargetDownloadEntries, buildQualityRowViews, conceptBelongsToTargetRepo, conceptForMapping, findTargetRowView, formatBridgeTargetDownloadEntry, resolveAICandidateID, getScoreDetails, getAIAnalysisCandidateIDs, withCachedConcept, withCandidateNames, withOwnNames, withSavedMatch } from './viewBuilders.js'
+import { buildBridgeTargetDownloadEntries, buildQualityRowViews, conceptBelongsToTargetRepo, conceptForMapping, findTargetRowView, formatBridgeTargetDownloadEntry, resolveAICandidateID, getScoreDetails, getAIAnalysisCandidateIDs, withCachedConcept, withCandidateNames, buildMatchEntries, restoredNote, withOwnNames, withSavedMatch } from './viewBuilders.js'
 import { formatClockTime, getCapacityWaitLabel, mergeCapacityWaits } from './rowProgress.js'
 
 import './MapProject.scss'
@@ -1563,7 +1563,7 @@ const MapProject = () => {
         _states[state] = _states[state] || []
         _states[state].push(index)
         _decisions[index] = (data['__Decision__'] || data['__row_decision__']) === t('map_project.none') ? undefined : (data['__Decision__'] || data['__row_decision__'])
-        _notes[index] = data['__Note__']
+        _notes[index] = restoredNote(data['__Note__'], savedMatches[index])
         _mapTypes[index] = data['__Map Type__'] || data['__map_type__']
         _proposed[index] = (data['__Proposed__'] || data['__proposed__']) ? JSON.parse(data['__Proposed__'] || data['__proposed__']) : undefined
         data = omit(data, [...reservedKeys, ...optionalReservedKeys])
@@ -1717,7 +1717,7 @@ const MapProject = () => {
     const projectLogsForSave = options.projectLogs || projectLogsRef.current
     setIsSaving(true)
     const f = getFileObjectFromRows()
-    const selected = map(mapSelected, (data, i) => {
+    const selected = buildMatchEntries(map(data, row => row.__index), mapSelected, notes, (data, i) => {
       return {
         url: data?.url,
         repoURL: data?.repo?.version_url || data?.repo?.url,
diff --git a/src/components/map-projects/__tests__/views.test.js b/src/components/map-projects/__tests__/views.test.js
index 88865fd..a7d7636 100644
--- a/src/components/map-projects/__tests__/views.test.js
+++ b/src/components/map-projects/__tests__/views.test.js
@@ -28,7 +28,9 @@ import {
   withCachedConcept,
   withCandidateNames,
   withOwnNames,
-  withSavedMatch
+  withSavedMatch,
+  buildMatchEntries,
+  restoredNote
 } from '../viewBuilders.js'
 
 // ---------- Helpers ----------
@@ -831,3 +833,30 @@ test('withOwnNames: a mapped target keeps its own names and highlight over a can
   assert.equal(withOwnNames(withNames, searchedTarget).names, glucoseNames)
   assert.deepEqual(withOwnNames(withNames, searchedTarget).search_meta.search_highlight, { name: ['x'] })
 })
+
+// ---------- unmapped row notes (OpenConceptLab/ocl_issues#2984) ----------
+
+// The save's entry for a row `mapSelected` holds, as onSave builds it.
+const entryFor = (target, index) => ({rowIndex: index, url: target?.url, note: notesFixture[index] || undefined})
+let notesFixture = {}
+
+// Save, serialise, reopen: what MapProject sends and what it restores.
+const roundTrip = (mapSelected, notes, rows) => {
+  notesFixture = notes
+  const sent = JSON.parse(JSON.stringify(buildMatchEntries(rows, mapSelected, notes, entryFor)))
+  const saved = Object.fromEntries(sent.map(entry => [entry.rowIndex, entry]))
+  return {sent, restored: Object.fromEntries(rows.map(index => [index, restoredNote(undefined, saved[index])]))}
+}
+
+test('a note on an unmapped row survives save and reopen', () => {
+  const { sent, restored } = roundTrip({0: searchedTarget}, {0: 'mapped note', 1: 'needs a clinician', 2: ''}, [0, 1, 2])
+  assert.deepEqual(sent.map(entry => entry.rowIndex), ['0', 1])
+  assert.deepEqual(restored, {0: 'mapped note', 1: 'needs a clinician', 2: undefined})
+  assert.equal(restoredNote('csv note', sent[1]), 'csv note')
+})
+
+test('a cleared row (null in mapSelected) with a note is sent once and keeps its note', () => {
+  const { sent, restored } = roundTrip({0: null}, {0: 'rejected: wrong unit'}, [0])
+  assert.equal(sent.length, 1)
+  assert.equal(restored[0], 'rejected: wrong unit')
+})
diff --git a/src/components/map-projects/viewBuilders.js b/src/components/map-projects/viewBuilders.js
index 411ce42..af49291 100644
--- a/src/components/map-projects/viewBuilders.js
+++ b/src/components/map-projects/viewBuilders.js
@@ -480,6 +480,25 @@ export const withSavedMatch = (target, savedMatch) => {
   }
 }
 
+/**
+ * The `matches` a save sends: one entry per row. `entryFor` builds the entry
+ * of each row `mapSelected` holds, a cleared one (a null) included. A row it
+ * holds no key for, with a review note, gets a note-only entry, as the note is
+ * kept only in its entry (OpenConceptLab/ocl_issues#2984).
+ */
+export const buildMatchEntries = (rowIndexes, mapSelected, notes, entryFor) => [
+  ...Object.entries(mapSelected).map(([index, target]) => entryFor(target, index)),
+  ...rowIndexes
+    .filter(index => !Object.prototype.hasOwnProperty.call(mapSelected, index) && notes[index])
+    .map(index => ({rowIndex: index, note: notes[index]}))
+]
+
+/**
+ * A row's review note on reopen: the one its CSV row holds, else the one its
+ * saved `matches` entry holds (OpenConceptLab/ocl_issues#2984).
+ */
+export const restoredNote = (csvNote, savedMatch) => csvNote || savedMatch?.note || undefined
+
 /**
  * A mapped target with its own names and match highlight put back over a
  * candidate's: the ones it was mapped with, or that a reopened project