The aim of the study was to determine the effect of balanced diet on selected parameters of oxidative stress, immunological response and nutritional status in patients undergoing haemodialysis (HD) due to diabetic kidney disease. Forty HD patients took part in the study. The nutritional status and diets of all the patients were initially assessed and the patients were divided into two groups. The control group (C) got unchanged diet regarded by those patients as optimal. For patients in the P group, a standard diet for a patient undergoing haemodialysis treatment was introduced, considering the fundamental disease – diabetes. Albumin, total protein, leptin and interleukin 6 (IL-6) and tumor necrosis factor  (TNF-) cytokine concentrations were determined in blood plasma, and CAT and SOD enzymes activity was determined in erythrocytes by the spectrophotometric method. On the basis of the results of BMI, albumin and total protein analyses it can be stated that a well-balanced diet can limit the loss of body weight. Performed studies show that the proper diet can reduce the secretion of proinflammatory cytokines and ensure proper activity of antioxidative enzymes in the blood of HD patients.