Introduction: Diabetes type 2 is caused by tissue insulin resistance and impaired insulin secretion by pancreatic beta cells, which leads to unfavorable changes in the metabolism of carbohydrates, fats and proteins. These phenomena result in the development of oxidative stress in beta cells as well as in other insulin target tissues. The treatment of patients with diabetes should be directed to prevent the formation of oxidative stress, which to some extent can protect the patient from vascular complications. Aim: The aim of the study was to determine the effect of the comprehensive balneological treatment on total antioxidative status (TAS) in patients with diabetes type 2. Material and Methods: The study was carried out in 21 patients with diabetes treated at the Ciechocinek Health Resort Clinical Hospital. All patients were subjected to the comprehensive balneological treatment, which included baths and exercises in a saline pool (17 treatments), mud compresses (17 treatments), carbonic baths (17 treatments), diabetic diet and pharmacological treatment. All patients had clinical and laboratory tests performed before and after the treatment. Laboratory tests included: plasma total antioxidant status (TAS), plasma uric acid concentration and plasma lipid profile. Glycemia was controlled daily fasting and two hours after a meal. Finally, a statistical analysis of results obtained before and after the treatment was made. Results: The plasma total antioxidant status (TAS) increased significantly in all subjects after the treatment. The mean TAS value after the treatment (378.98 micromol/L) was significantly higher than before the treatment (158.82 micromol/L) with p = 0.00006. The level of plasma uric acid did not change significantly. The total cholesterol level was reduced: before the treatment the mean value was 198.43 mg/dL, while after the treatment -190.38 mg/dL. The difference was statistically significant (p = 0.046). The LDL cholesterol was also decreased after the treatment (before 117.19 mg/dL vs after 105.38 mg/dL, p = 0.01). There were no differences in the HDL cholesterol or triglyceride levels. Diabetes was metabolically balanced in studied patients, especially after the health resort treatment. Conclusions: The treatment program applied in patients with diabetes, including balneological treatments along with diet and pharmacotherapy, improves carbohydrate-lipid disorders and peripheral circulation, and increases plasma TAS. This indirectly indicates on the reduction or prevention of oxidative stress.