Appendiceal mucocele is a rare entity which is characterised by cystic dilatation due to abnormal accumulation of mucus in the lumen of the appendix. It is usually asymptomatic and radiologically observed as cystic mass in the right lower quadrant. We report a case regarding 60-year-old woman presenting with right adnexal mass. Mucocele of appendix was detected intraoperatively and diagnosis was confirmed pathologically. Appendiceal mucocele should be included in the differential diagnosis of the cystic masses observed at the right lower quadrant.