Fibromyalgia (FM) causes generalized musculoskeletal pain and sexual life may also be impaired in these patients. We aimed to study sexual performance in FM patients comparing them with healthy controls and verify if there is association of epidemiological variables, degree of musculoskeletal pain and associated diseases with sexual performance in this group of patients. This is a cross-sectional study based in an internet survey. FM and controls filled a questionnaire on epidemiological data, associated diseases, and musculoskeletal pain. Also answered the validate questionnaires Female Sexual Function Index (FSFI) and the Sexual Quotient-Females (SQ-F) to evaluate the sexual performance. The survey was answered for 1584 individuals: 726 FM patients and 858 paired controls. Sexual performance evaluated by FSFI and by SQ-F was worse in the FM group than controls in all studied domains (all with p < 0.0001). According to SQ-F, 63% of them had a regular to null performance; according to FSFI, 83% had sexual dysfunction. Sexual performance was worse in those on menopause (< 0.0001). A modest correlation of age (rho – 0.09 for SQ-F and – 0.10 for FSFI) and degree of musculoskeletal pain (rho = - 0.21 for SQ-F and – 0.23 for FSFI) with sexual performance indexes were found. Psychiatric illness was also associated with lower SQ-F (p = 0.001). There is a high prevalence of sexual dysfunction in FM that associates with the presence of menopause, psychiatric comorbidities, older age, and high degree of musculoskeletal pain.