Objective: To estimate the prevalence of premature ovarian failure (POF) and its associated factors in patients with systemic lupus erythematosus (SLE)., Methods: Cross-sectional study including consecutive SLE women <60 years of age attending a rheumatology clinic. A face-to-face interview was undertaken to obtain demographic, gynaecological and lupus characteristics. Additional rheumatologic and endocrine data were retrieved from patients' medical records. POF prevalence was estimated in the study sample and in a subgroup of patients aged <40 years at interview. Associations between POF and selected variables were assessed by logistic regression analyses., Results: A total of 961 patients were analysed. Prevalence of POF, secondary amenorrhea of known cause, menopause and hysterectomy were 5.4%, 0.8%, 7.8% and 4.4%, respectively. In 674 (70%) patients who had not been exposed to cyclophosphamide (CYC) the prevalence of POF was 0.6%. Disease activity over time (OR 1.4 (CI 95% 1.0-1.8, p < 0.05)) and CYC treatment (OR 5.9 (CI 95% 1.8-18.8, p < 0.01)) were associated with higher prevalence. Association between POF and endocrine autoimmune diseases was not found., Conclusions: In the absence of CYC treatment, the prevalence of POF in lupus patients is consistent with that reported in the general population. The existence of autoimmune processes at the ovary seems unlikely in most lupus patients., (© The Author(s) 2015.)