The authors report a case of leiomyomatosis peritonealis disseminata in a non pregnant woman. The numerous nodules were first considered by the surgeon as a disseminated abdominal carcinoma, fact which often happens in the literature. Diagnosis was changed on frozen section showing histologically benign appearing smooth muscle cells, consistent with leiomyomatosis peritonealis disseminata this diagnosis was confirmed by examination of. Paraffin sections. Though electron microscopic studies favor the smooth-muscle nature of the cells, the proper origin of this disease is still unknown : the role of oestrogens and metaplasia of the subcoelomic mesenchyme are discussed.