Turkey is the fifth country in Europe with regard to the number of patients receiving haemodialysis (HD). However, only a limited number of studies have comparatively investigated the factors that affect quality of life in haemodialysis and peritoneal dialysis (PD) patients in Turkey. The purpose of the study was to investigate the factors that affect quality of life in haemodialysis and peritoneal dialysis patients, as well as providing a comparison of quality of life between these groups. In this cross-sectional study, Quality of Life Scale and a data form was completed by 300 dialysis patients who received treatment at five hospital-based dialysis units in Istanbul, Turkey. The data were evaluated using arithmetic mean values, standard deviations, minimums, maximums, percentages, independent groups t-tests, Spearman correlation analyses and one-way variance analyses. The quality of life values in peritoneal dialysis patients were found to be higher than those of haemodialysis patients (P < 0.05). It was concluded that the quality of life in chronic dialysis patients was affected by various factors.