Histological analysis of 89 "benign" ovarian cysts received over a period of 2-1/2 years (January, 1991 to July, 1993) at the department of Pathology, Fatima Jinnah Medical College, Lahore showed that 44 were neoplastic, 22 dysfunctional, 19 simple and 4 endometriotic. Clinical presentation and gross features could not serve to differentiate these types. Routine histological examination had to be supplemented with ample blocking and deeper sections for a more specific typing. With this procedure the original diagnosis was altered in 11.2% cases, 7 cases originally labelled as "simple cysts", were categorized as dysfunctional (N = 2), neoplastic (N = 1) and endometriotic cysts (N = 3). Similarly in 3 cases the primary diagnosis of endometriotic cysts was altered in favour of dysfunctional (N = 2) and neoplastic (N = 1) cysts. The neoplastic and dysfunctional cysts have different clinical implications. It is proposed that the clinical diagnosis of benign ovarian cyst should be supported by a careful histological evaluation.