Gastrooesophageal reflux (GER) may participate in the development and persistence of asthmatic complaints. For its detection various examination methods may be used such as oesophagography, oesophageal manometry and pH-metry, ultrasonography, isotope scintigraphy, oesophagoscopy. By means of these methods we detected GER in 27 children, i. e. 41% of a total number of 65 asthmatic children with a medium severe and severe form of the disease. Because of failure of conservative treatment of reflux and hitherto used anti-asthmatic therapy, in 1984 to 1986 in 11 children surgical treatment of reflux by Nissen's fundoplication was indicated. The group comprised 9 boys and 2 girls aged 2 to 14 years. The effect of the operation was evaluated after an interval of 1.5 to 3.5 years following operation. Surgical treatment was successful in four patients (36%) and partly successful in 5 patients (45%). Despite these encouraging results the indication surgery in GER in asthmatic patients still is strictly individual.