Obesity is known to be one of the risk factors of gastroesophageal reflux disease (GERD), the most widespread oesophageal pathology. The elevated body mass index is associated not only with the increased severity of clinical symptoms (heartburn and regurgitation) but also with the enhanced frequency of erosive forms of GERD and Barrett’s oesophagus. The mechanisms underlying the development of obesity-associated gastroesophageal reflux disease vary from a rise in the visceral fat content, disturbances of the gastric and oesophageal motility to the increased frequency of lower oesophageal sphincter relaxations. The authors discuss the influence of metabolic syndrome and adipokines on the motility of the upper segments of the gastrointestinal tract (GIT). It is concluded that the relationship between the excessive body weight and diseases of the upper gastrointestinal tract needs to be further investigated bearing in mind both the increasingly greater number of the subjects suffering from obesity and the growing incidence of gastroesophageal reflux disease in the population.