diff --git a/surveys.go b/surveys.go
index 48df3eb..ad44b0a 100644
--- a/surveys.go
+++ b/surveys.go
@@ -77,11 +77,12 @@ func declareAPIAuthSurveysRoutes(router *gin.RouterGroup) {
 	surveysRoutes.Use(surveyHandler)
 
 	surveysRoutes.GET("/score", func(c *gin.Context) {
+		loggedUser := c.MustGet("LoggedUser").(*User)
 		var u *User
 		if user, ok := c.Get("user"); ok {
 			u = user.(*User)
 		} else {
-			u = c.MustGet("LoggedUser").(*User)
+			u = loggedUser
 		}
 		s := c.MustGet("survey").(*Survey)
 
@@ -93,10 +94,29 @@ func declareAPIAuthSurveysRoutes(router *gin.RouterGroup) {
 				return
 			}
 
-			if score == nil {
-				c.JSON(http.StatusOK, map[string]string{"score": "N/A"})
-			} else {
+			if score != nil {
 				c.JSON(http.StatusOK, map[string]float64{"score": *score})
+			} else if _, ok := c.Get("user"); !ok && loggedUser.IsAdmin {
+				// Admin retrieve mean score
+				scores, err := s.GetGrades()
+				if err != nil {
+					log.Printf("Unable to GetGrades(sid=%d): %s", s.Id, err.Error())
+					c.AbortWithStatusJSON(http.StatusInternalServerError, gin.H{"errmsg": "An error occurs when trying to retrieve grades."})
+					return
+				}
+
+				*score = 0
+				nbGrades := 0
+				for _, s := range scores {
+					*score += *s
+					nbGrades += 1
+				}
+
+				*score /= float64(nbGrades)
+
+				c.JSON(http.StatusOK, map[string]float64{"score": *score})
+			} else {
+				c.JSON(http.StatusOK, map[string]string{"score": "N/A"})
 			}
 		} else {
 			c.AbortWithStatusJSON(http.StatusForbidden, gin.H{"errmsg": "Not accessible"})