Familial Mediterranean fever (FMF) is an autosomal recessive disease characterized by short lived, febrile serosal inflammatory attacks. Although majority of patients have random pattern of attacks, some reports described precipitating factors. There are also contradictory reports relating FMF attacks with menstruation and the natural course of their pregnancies. Seventy-two female patients with FMF with a mean age of 34.9+/-12.4 were interviewed. A standardized questionnaire was used inquiring any associations of FMF attacks of the patients with their menstruations and pregnancies. Thirty-eight patients (53%) reported that their attacks frequently coincided with their menstrual cycles and 17 patients noticed pleuritic chest pain in addition to their abdominal attacks. One patient experienced only febrile pleural attacks during her menstrual cycles. Unlike dysmenorrhoea, none of these patients' attacks responded to non-steroidal anti-inflammatory drugs. All of the patients could correctly differentiate their FMF attacks from dysmenorrhoea. Forty patients could give detailed information about the frequency and severity of their FMF attacks during 73 pregnancies: 25 patients (62.5%) experienced complete symptomatic remissions; the attacks were aggravated (7 patients), ameliorated (6 patients) or did not change (2 patients) in the rest of the pregnancies. Four patients continued to use colchicine during their pregnancies and delivered healthy babies. One patient gave birth to a child with Down's syndrome although she was not on colchicine therapy. Although FMF attacks and discomforts of menstrual cycles do overlap frequently, patients can easily differentiated them. Patients can be reasonably assured that the period of pregnancy will be comfortable but abstaining from colchicine should not be recommended. Gynecologists must be aware of FMF in the differential diagnosis of dysmenorrhoea or endometriosis.