A proper nutritional approach and regular physical activity are important to improve the quality of life and to maintain physical ability in renal patients treated with peritoneal dialysis. Physical inactivity and poor nutritional status are common in renal patients, because of the restrictive diet, appetite loss and poor physical fitness. The aim of this clinical study was to analyse dietary intake of 19 patients. We compared the dietary intake with their body composition, measured with bio impendance spectroscopy. With simple tests such as hand grip test and sit to stand test, we assesed the patients physical ability and compared the results with their nutritional status. Average caloric intake of 19 patients is 1545 ± 295 kcal/day, or 21,4 kcal/kg body weight /day, average protein intake is 0,8 g/kg body weight/day, average phosphorus intake is 0,8 ± 0,2 g/day and average potassium intake is 1,9 ± 0,5 g/day. Average BMI (body mass index) is 24,4 ± 2,9 kg/m2, average phase angle is 5,2 ± 0,9, average LTI (lean tissue index) is 14,5 ± 2,8 kg/m2 and average FTI (fat tissue index) is 9,3 ± 3,6 kg/m2. Average energy intake and protein intake is inadequate according to the dietary recommendations for patients treated with peritoneal dialysis. Average phosphorus intake and potassium intake corresponds to the recommendations. The results of the hand grip test showed hand grip weakness and reduced muscle strenght among observed patients. Patients report a lack of motivation and energy, which are associated with low levels of physical activity. The results of this study will help us diagnose our patients nutritional status, so we can find suitable measurements to ensure the proper rehabilitation and improve our patients quality of life.