The mucocele of appendix or mucosecreting tumor is a rare affection defined as a cystic dilatation of the light of the appendix following the intra luminal accumulation of mucinous, translucent, gelatinous, secretion which may reach either the entire organ or a segment more often distal. The pathogenesisis is discussed; the diagnosis is more often preoperative. The therapeutic depends on the histological nature. This goes from the simple appendicectomy, whose shapes are benign to the right hemicolectomy in the malignant mucocele. We report a case collaged in the general surgical service of the 5^th Military Hospital.