Background. Sleep quality (SQ) is a significant problem in peritoneal dialysis (PD) patients, yet the underlying factors are not well known. In addition, depression and impaired quality of life (QOL) are main problems in PD patients. We measured the SQ and investigated the effect of depression, QOL, and some other factors on SQ in PD patients. Methods. Data were collected from 124 PD patients (59 male, 65 female) in our center. Demographic data and laboratory values were analyzed. All patients were asked to complete the Pittsburgh Sleep Quality Index (PSQI), Beck Depression Index (BDI), and SF-36. Results. Mean age of the patients was 52.6 ± 14.3 year. The prevalence of poor SQ was 43.5%, defined as global PSQI score >5. The prevalence of depression was 25.8%, defined as BDI scores >17. The poor sleepers had higher BDI scores, poor QOL, older age, and lower duration of PD compared to the good sleepers. There was not a difference in hemoglobin, albumin, C-reactive protein, Kt/V, urea, creatinine, lipid parameters, gender, marital status, cigarette smoking, mode of PD, and comorbidity between poor and good sleepers. The global PSQI score was correlated negatively with both PCS and MCS (r = -0.414, r = -0.392, respectively; p < 0.001) and correlated positively with BDI scores and age (r = 0.422, p < 0.001 and r = 0.213, p = 0.018, respectively). In multivariate analysis, only BDI scores were found to be factors that could predict the patients being poor sleepers. Conclusion. Poor SQ is a significant problem in PD patients, and we found an association with depression, QOL, and age. Regular assessment and management of SQ may be important especially with PD patients who are depressive and elderly to increase QOL. Copyright © Informa Healthcare USA, Inc.