Introduction: To date, there are no descriptions in the literature on gynecologic and sexual function evaluation in female patients with dermatomyositis (DM) and polymyositis (PM). Objective: To assess sexual function in female patients with DM/PM. Patients and methods: This is a monocentric, cross-sectional study in which 23 patients (16 DM and 7 PM), with ages between 18 and 40 years, were compared to 23 healthy women of the same age group. Characteristics on sexual function were obtained by applying the questionnaires Female Sexual Quotient (FSQ) and Female Sexual Function Index (FSFI) validated for the Brazilian Portuguese language. Results: The mean age of patients was comparable to controls (32.7 +/- 5.3 vs. 31.7 +/- 6.7 years), as well as the distribution of ethnicity and socioeconomic class. As for gynecological characteristics, patients and healthy controls did not differ with respect to age at menarche and percentages of dysmenorrhea, menorrhagia, premenstrual syndrome, pain at mid-cycle, mucocervical secretion, and vaginal discharge. The FSQ score, as well as all domains of the FSFI questionnaire (desire, arousal, lubrication, orgasm and satisfaction), were significantly decreased in patients versus controls, with 60.9% of patients showing some degree of sexual dysfunction. Conclusions: This was the first study to identify sexual dysfunction in patients with DM/PM. Therefore, a multidisciplinary approach is essential for patients with idiopathic inflammatory myopathies, in order to provide prevention and care for their sexual life, providing a better quality of life, both for patients and their partners. (C) 2016 Elsevier Editora Ltda.