The aim of the study was to compare autonomic function and gastric myoelectric activity in patients with type 1 and 2 of diabetes. We used the skin electrodes for recording gastric myoelectric activity (EGG) and the heart rate variability (HRV). Patients were divided into two groups. The first group: 19 patients with IDDM. The second-16 patients with NIDDM. We made two comparative control groups, matched with age and gender. We conclude, that decrease in gastric myoelectric activity was observed in both groups of patients, mostly in 1 group (IDDM) of patients. There was increase of heart rate and reduction of spectral analysis parameters in both types of diabetic. In patients with type 1 we noticed the increase of sympathetic activity (LF/HF ratio increased). In patients with type 2 there was the non significant decrease in sympathetic activity (LF/HF ratio decreased). On the basis of our observations we confirmed the correlation among autonomic function tested by HRV and changes of stomach electric activity. Decrease in HRV and gastric myoelectric activity could be indicating damage of parasympathetic system in IDDM.