Objective: Verify the factors associated with poor sleep quality among postmenopausal women. Methods: Cross-sectional, descriptive, observational study conducted with 185 postmenopausal women assisted at the outpatient clinic of Santa Casa de Sao Paulo. Data were collected regarding sleep quality using the Pittsburgh Sleep Quality Index (PSQI); quality of life according to the WHO Quality of Life-BREF (WHOQOL-BREF) and the Alcohol Use Disorders Identification Test (AUDIT); and through the application of a questionnaire including information on socioeconomic profile, age of menopause, natural or surgical menopause, smoking, chronic diseases, use of hormonal therapy, hot flashes, and alcohol consumption. Data were analyzed using STATA 13 statistical software. Variables were compared by mean and standard deviation. Regression analysis was used to verify the possible factors associated with quality of sleep. The coefficients are considered significant when p<0.10. results: 57.28% of the women investigated presented poor sleep or sleep disturbance. Negative correlation was observed between quality of sleep and smoking (p=0.083), whereas positive correlation was found between poor sleep quality and number of hot flashes (p=0.00). In addition, the earlier the menopause, the worse the quality of sleep (p=0.05). conclusions: The following factors negatively influencing postmenopausal women's quality of sleep were identified: smoking, number of hot flashes, and age of menopause. It is not possible to identify causality; however, worsening sleep quality was identified when these factors were present.