Electrogastrography (EGG) is study with big interest and hope in last years. Uninvasion character of electrogastrography may have wide employment in diagnostician of digestive tract in it gastrooesophageal reflux. The aim of the study was analyze gastric myoelectrical activity in children and youth with gastrooesophageal acid reflux. Material and methods: 130 children and youth aged 6 to 18 years were diagnosed in Chair and Clinic of Pediatrics, Allergology and Gastroenterology by the reason of suspicion gastrooesophageal reflux. All patients had 24-hour pH-metry and electrogastrography. Patients were divided into two groups on base of result pH-metry. Group I – with gastrooesophageal acid reflux n=100. Group II – without gastrooesophageal acid reflux n=30. Gastric myoelectrical activity was performed using multichannel electrogastrography (POLIGRAM NETTM). The analysis of EGG included: dominant frequency (DF), the power of the dominant frequency (DP), percentage of normal, bradygastria, tachygastria, arrhythmia, dominant frequency instability coefficient (DFIC), dominant power instability coefficient (DPIC) recorded from each of four channels (C1, C2, C3, C4) and average percentage slow wave coupling (%SWC) among channels. Results: In comparison to patients of group II in group I were recorded significantly higher percentage of arrhythmia frequency in C2 and C3 (27.48% vs 20.54%; p=0.04 and 26.49% vs 16.86%; p=0.004), significantly lower percentage of tachygastria frequency in C1 (2.61% vs 2.67%; p=0.036) and significantly lower percentage of normogastria frequency in C3 (69.4% vs 79.47%; p=0.007). In group I fasting were observed significantly higher dominant power instability coefficient (DPIC) (1.5% vs 1.1%; p=0.012) in C2 and significantly lower percentage of SWC in C1 C3 (62.53% vs 69.16%; p=0.039). In group I postprandialy were observed significantly higher percentage of arrhythmia frequency in C2 and C3 (14.78% vs 10.81%; p=0.023 and 17.63% vs 10.28%; p=0.003), significantly higher percentage of bradygastria frequency in C4 (5.77% vs 3.83%; p=0.046) and significantly lower percentage of normogastria frequency in C3 (70.42% vs 78.15%; p=0.046). Conclusion: The own results confirm that disturbances of gastric myoelectrical activity in children and youth with gastrooesophageal acid reflux were equal in period before and after meal. The disturbances concerned mainly boost of arrhythmia frequency.