diff --git a/internal/gapicgen/generator/generator.go b/internal/gapicgen/generator/generator.go
index 7b13ff9a67cb..c3e129b84b17 100644
--- a/internal/gapicgen/generator/generator.go
+++ b/internal/gapicgen/generator/generator.go
@@ -23,6 +23,8 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
+	"sort"
+	"strings"
 
 	"cloud.google.com/go/internal/gapicgen/git"
 )
@@ -69,7 +71,43 @@ func gatherChanges(googleapisDir, genprotoDir string) ([]*git.ChangeInfo, error)
 	if err != nil {
 		return nil, err
 	}
-	changes, err := git.ParseChangeInfo(googleapisDir, commits)
+	affectedProtos := make(map[string][]string)
+	var relevantCommits []string
+	for _, commit := range commits {
+		files, err := git.FilesChanged(googleapisDir, commit)
+		if err != nil {
+			return nil, err
+		}
+		protos := make(map[string]struct{})
+		for _, file := range files {
+			if !strings.HasSuffix(file, ".proto") {
+				continue
+			}
+			pkg, err := goPkg(filepath.Join(googleapisDir, file))
+			if err != nil {
+				return nil, err
+			}
+			var onWatchlist bool
+			for _, watchedPkg := range generateList {
+				if pkg == watchedPkg {
+					onWatchlist = true
+					break
+				}
+			}
+			if onWatchlist {
+				if _, ok := affectedProtos[commit]; !ok {
+					relevantCommits = append(relevantCommits, commit)
+				}
+				protos[file] = struct{}{}
+			}
+		}
+		for proto := range protos {
+			affectedProtos[commit] = append(affectedProtos[commit], proto)
+		}
+		sort.Strings(affectedProtos[commit])
+	}
+
+	changes, err := git.ParseChangeInfo(googleapisDir, relevantCommits, affectedProtos)
 	if err != nil {
 		return nil, err
 	}
diff --git a/internal/gapicgen/git/git.go b/internal/gapicgen/git/git.go
index 114a233e6e30..56d7e020deff 100644
--- a/internal/gapicgen/git/git.go
+++ b/internal/gapicgen/git/git.go
@@ -33,6 +33,7 @@ type ChangeInfo struct {
 	Body           string
 	Title          string
 	GoogleapisHash string
+	AffectedProtos []string
 }
 
 // FormatChanges turns a slice of changes into formatted string that will match
@@ -73,11 +74,18 @@ func truncateAndFormatChanges(changes []*ChangeInfo, onlyGapicChanges, truncate
 		if truncate {
 			startBody := strings.Index(body, "PiperOrigin-RevId")
 			if startBody != -1 {
-				body = fmt.Sprintf("  %s", body[startBody:])
+				body = "  " + body[startBody:]
 			}
 		}
 
-		sb.WriteString(fmt.Sprintf("%s\n\n", body))
+		sb.WriteString(fmt.Sprintf("%s\n", body))
+		if len(c.AffectedProtos) > 0 {
+			sb.WriteString("  Affected protos:\n")
+			for _, proto := range c.AffectedProtos {
+				sb.WriteString(fmt.Sprintf("  - %s\n", proto))
+			}
+		}
+		sb.WriteString("\n")
 	}
 	// If the buffer is empty except for the "Changes:" text return an empty
 	// string.
@@ -88,7 +96,7 @@ func truncateAndFormatChanges(changes []*ChangeInfo, onlyGapicChanges, truncate
 }
 
 // ParseChangeInfo gets the ChangeInfo for a given googleapis hash.
-func ParseChangeInfo(googleapisDir string, hashes []string) ([]*ChangeInfo, error) {
+func ParseChangeInfo(googleapisDir string, hashes []string, affectedProtos map[string][]string) ([]*ChangeInfo, error) {
 	var changes []*ChangeInfo
 	for _, hash := range hashes {
 		// Get commit title and body
@@ -112,6 +120,7 @@ func ParseChangeInfo(googleapisDir string, hashes []string) ([]*ChangeInfo, erro
 			Title:          title,
 			Body:           body,
 			GoogleapisHash: hash,
+			AffectedProtos: affectedProtos[hash],
 		})
 	}
 	return changes, nil
@@ -182,9 +191,9 @@ func DeepClone(repo, dir string) error {
 	return err
 }
 
-// filesChanged returns a list of files changed in a commit for the provdied
+// FilesChanged returns a list of files changed in a commit for the provided
 // hash in the given gitDir.
-func filesChanged(gitDir, hash string) ([]string, error) {
+func FilesChanged(gitDir, hash string) ([]string, error) {
 	c := execv.Command("git", "show", "--pretty=format:", "--name-only", hash)
 	c.Dir = gitDir
 	b, err := c.Output()
diff --git a/internal/gapicgen/git/git_test.go b/internal/gapicgen/git/git_test.go
index 35f4cf214893..f69248aa38b4 100644
--- a/internal/gapicgen/git/git_test.go
+++ b/internal/gapicgen/git/git_test.go
@@ -68,6 +68,12 @@ func TestFormatChanges(t *testing.T) {
 			onlyGapics: true,
 			want:       "",
 		},
+		{
+			name:       "affected protos",
+			changes:    []*ChangeInfo{{Title: "fix: foo", Body: "bar", AffectedProtos: []string{"foo.proto", "bar.proto"}}},
+			onlyGapics: false,
+			want:       "\nChanges:\n\nfix: foo\n  bar\n  Affected protos:\n  - foo.proto\n  - bar.proto\n\n",
+		},
 	}
 
 	for _, tc := range tests {