Abstract Objectives To date, there is almost no information concerning the sexual health of patients with idiopathic inflammatory myopathies (IIM). This cross-sectional study aimed to compare sexual function in patients with IIM to age-/sex-matched healthy controls (HC) and determine the potential impact of clinical features on sexual function. Methods In total, 122 women (61 with IIM, 61 age-matched HC) and 22 men (11 with IIM, 11 age-matched HC) aged 18–80 years completed gender-specific selection of 7 well-established and validated questionnaires assessing sexual health and function (Female Sexual Function Index, Brief Index of Sexual Function for Women, Sexual Function Questionnaire, Sexual Quality of Life Questionnaire–Female, International Index of Erectile Function, Male Sexual Health Questionnaire, Sexual Quality of Life Questionnaire–Male). Results were compared between patients and HC and correlated with selected disease-related features. Results The prevalence of sexual dysfunction in IIM was 59% in women (vs 40% in HC), and 64% (vs 9% in HC) in men. Men and women with IIM reported significantly impaired sexual function compared with sex-/age-matched HC. Decreased sexual function was associated with muscle weakness, disability, physical inactivity, fatigue, depression and decreased quality of life. Conclusions Our results suggest that sexual dysfunction is common among IIM patients and more attention should be paid to this aspect of the disease.