A cross-sectional study of 310 hemodialysis patients in three centers in Sri Lanka found that 83.3% of patients had poor sleep quality according to the Pittsburgh Sleep Quality Index (PSQI). The main factors were poor sleep latency and short sleep duration. There was a significant association with number of dialysis sessions per week (p=0.001), serum phosphorus level (p=0.016), total number of dialysis side effects (p<0.01), recovery time (p<0.01) and post-dialysis urea concentration (p=0.027). Adequacy of dialysis (Kt/V, p=0.001), sodium level after dialysis (p=0.006) and hemoglobin level (p=0.005) showed negative correlations. There were differences in sleep quality between patient categories (p=0.032), appetite (p<0.01) and dialysis centers (p<0.01). According to multiple linear regression, significant predictors were dialysis center, vascular access, number of dialysis side effects, appetite, and postdialysis urea level. The study recommends further research into interventions against poor sleep quality.