diff --git a/ui/src/lib/works.js b/ui/src/lib/works.js
index 1d5976c..c87dd0f 100644
--- a/ui/src/lib/works.js
+++ b/ui/src/lib/works.js
@@ -109,6 +109,18 @@ export class Work {
     }
   }
 
+  async addMissingGrades() {
+    const res = await fetch(`api/works/${this.id}/grades`, {
+      method: 'PATCH',
+      headers: {'Accept': 'application/json'},
+    });
+    if (res.status == 200) {
+      return (await res.json()).map((g) => new Grade(g));
+    } else {
+      throw new Error((await res.json()).errmsg);
+    }
+  }
+
   async getSubmission(uid) {
     const res = await fetch(uid?`api/users/${uid}/works/${this.id}/submission`:`api/works/${this.id}/submission`, {
       headers: {'Accept': 'application/json'}
diff --git a/ui/src/routes/works/[wid]/+page.svelte b/ui/src/routes/works/[wid]/+page.svelte
index 9048e5f..df2a76f 100644
--- a/ui/src/routes/works/[wid]/+page.svelte
+++ b/ui/src/routes/works/[wid]/+page.svelte
@@ -40,6 +40,11 @@
          stats.mean = sum / grades.length;
      });
  }
+
+ async function addMissingStudents(w) {
+     await w.addMissingGrades();
+     refresh_grades(w);
+ }
 </script>
 
 {#if $user && $user.is_admin}
@@ -72,12 +77,22 @@
                 {#if stats.mean > 0}(moyenne&nbsp;: {Math.round(stats.mean*100)/100}, min&nbsp;: {stats.min}, max&nbsp;: {stats.max}){/if}
             </small>
         </h3>
-        <button
-            class="btn btn-light"
-            on:click={() => refresh_grades(w)}
-        >
-            <i class="bi bi-arrow-clockwise"></i>
-        </button>
+        <div>
+            <button
+                class="btn btn-outline-info"
+                title="Ajouter les étudiants manquant"
+                on:click={() => addMissingStudents(w)}
+            >
+                <i class="bi bi-people"></i>
+            </button>
+            <button
+                class="btn btn-light"
+                title="Rafraîchir l'affichage des notes"
+                on:click={() => refresh_grades(w)}
+            >
+                <i class="bi bi-arrow-clockwise"></i>
+            </button>
+        </div>
     </div>
     <div class="card mt-3 mb-5">
         {#await gradesP}
diff --git a/users.go b/users.go
index 5ed899b..26dcfe3 100644
--- a/users.go
+++ b/users.go
@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"log"
 	"net/http"
+	"regexp"
 	"strconv"
 	"strings"
 	"time"
@@ -169,6 +170,33 @@ func getUsers() (users []User, err error) {
 	}
 }
 
+func getFilteredUsers(promo uint, group string) (users []User, err error) {
+	// Avoid SQL injection: check group name doesn't contains harmful content
+	var validGroup = regexp.MustCompile(`^[a-z0-9-]*$`)
+	if !validGroup.MatchString(group) {
+		return nil, fmt.Errorf("%q is not a valid group name", group)
+	}
+
+	if rows, errr := DBQuery("SELECT id_user, login, email, firstname, lastname, time, promo, groups, is_admin FROM users WHERE promo = ? AND groups LIKE '%,"+group+",%' ORDER BY promo DESC, id_user DESC", promo); errr != nil {
+		return nil, errr
+	} else {
+		defer rows.Close()
+
+		for rows.Next() {
+			var u User
+			if err = rows.Scan(&u.Id, &u.Login, &u.Email, &u.Firstname, &u.Lastname, &u.Time, &u.Promo, &u.Groups, &u.IsAdmin); err != nil {
+				return
+			}
+			users = append(users, u)
+		}
+		if err = rows.Err(); err != nil {
+			return
+		}
+
+		return
+	}
+}
+
 func getPromos() (promos []uint, err error) {
 	if rows, errr := DBQuery("SELECT DISTINCT promo FROM users ORDER BY promo DESC"); errr != nil {
 		return nil, errr
diff --git a/works.go b/works.go
index e2d857d..6909cec 100644
--- a/works.go
+++ b/works.go
@@ -179,6 +179,49 @@ func declareAPIAdminWorksRoutes(router *gin.RouterGroup) {
 
 		c.JSON(http.StatusOK, grades)
 	})
+	worksRoutes.PATCH("/grades", func(c *gin.Context) {
+		w := c.MustGet("work").(*Work)
+
+		// Fetch existing grades
+		grades, err := w.GetGrades("")
+		if err != nil {
+			log.Printf("Unable to GetGrades(wid=%d): %s", w.Id, err.Error())
+			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "An error occurs during grades retrieval."})
+			return
+		}
+
+		// Create an index
+		known_users := map[int64]bool{}
+		for _, g := range grades {
+			known_users[g.IdUser] = true
+		}
+
+		// Fetch students list registered for this course
+		users, err := getFilteredUsers(w.Promo, w.Group)
+		if err != nil {
+			log.Printf("Unable to getFilteredUsers(%d, %s): %s", w.Promo, w.Group, err.Error())
+			c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "An error occurs during users retrieval."})
+			return
+		}
+
+		var toAdd []WorkGrade
+		for _, user := range users {
+			if _, ok := known_users[user.Id]; !ok {
+				toAdd = append(toAdd, WorkGrade{
+					IdUser:  user.Id,
+					Login:   user.Login,
+					Grade:   0,
+					Comment: "- Non rendu -",
+				})
+			}
+		}
+
+		if len(toAdd) > 0 {
+			w.AddGrades(toAdd)
+		}
+
+		c.JSON(http.StatusOK, toAdd)
+	})
 	worksRoutes.PUT("/grades", func(c *gin.Context) {
 		w := c.MustGet("work").(*Work)