Aim: This study aims to identify the predictors of poor sleep quality and the associations between depression, hope and sleep in a sample of 156 women with breast cancer prior to surgery. Background: The care and treatment of breast cancer is among the most important scientific challenges in public health. Sleep disturbances and depression are the important complaint of cancer patients. However, they are often neglected. Patients diagnosed with breast cancer also experience prejudice, fear of death, suffering, mutilation, fear of lymphedema, as well as feelings of social devaluation leading to hopelessness Several studies point to hope as an effective strategy to help patients cope with difficulties and achieve their goals, especially patients with cancer. Methods: This is a report of baseline data extracted from a longitudinal study. Data collection tools: Pittsburgh Sleep Quality Index, Beck Depression Inventory, and the Herth Hope Index. Data were analyzed with the Spearman's Rank Correlation test and Multiple Logistic Regression analysis. Results: The majority of women had tumors in initial stages (78.7%), reported poor sleep quality (58.9%), and had moderate to severe or severe depression (27.2%). Significant correlations were found between hope and depression (Spearman r = 0.4341), and between sleep quality and depression (Spearman r = 03938). Significant associations were found between poor sleep quality and pain, symptoms of menopause and depression. Depression and symptoms of menopause were independent predictors of poor sleep quality. Conclusion: The evaluation of sleep quality, depression and hope should be implemented in clinical practice. Increased hope lessens depression and may positively affect sleep quality, all of which improves quality of life for women with breast cancer. (C) 2017 Elsevier Inc. All rights reserved.