Gastroesophageal reflux disease (GERD) is one of the most common gastroenterological diseases. Therefore, the issues of diagnosis and the most effective treatment of GERD are extremely relevant. Achieving a stable positive result of treatment is impossible without taking into account the pathogenetic mechanisms of the development of GERD. Particularly relevant are the little-studied issues of the influence of humoral factors on the development of GERD in the course of treatment. One of the interesting biologically active substances is prostaglandin E2, the possible involvement of which in the mechanisms of the development of GERD is insufficiently reported. The aim of the study is to evaluate the effect of antireflux surgery on the level of prostaglandin E2 in blood serum and to verify that its changes after surgical treatment are associated with the decrease of gastroesophageal reflux and esophageal inflammation. Materials and methods. 35 patients were examined with GERD who underwent laparoscopic total antireflux fundoplication. There were 26 women (74.3 %) and 9 men (25.7 %). Their age is 55.3 ± 11.3. The control group consisted of 20 practically healthy people (women – 14 (70.0 %), men – 6 (30.0 %), average age – 56.7 ± 10.6). Immunoenzymatic analysis of prostaglandin E2 was performed in blood plasma, which was obtained according to a standard method. Determination of prostaglandin E2 (Prostaglandin E2 ELISA, KGE004B, RnD Systems) was carried out by the immunoenzymatic method based on the use of the “sandwich“ variant of the solid-phase immunoenzymatic analysis. The procedure was carried out on the immunoenzyme complex ImmunoChem-2100 (USA) at the Department of Clinical Laboratory Diagnostics in Zaporizhzhia State Medical University. Research on the level of prostaglandin E2 in the main group was carried out before surgical treatment and 2–3 months after surgery by taking venous blood and using the above test systems. Statistical evaluation of the research results was performed using the Statistica for Windows 13 software package (StatSoft Inc., No. JPZ804I382130ARCN10-J). Results. The level of prostaglandin E2 in the blood of practically healthy people was 16.7 ± 6.1 pg/ml. In the main group, the values of prostaglandin E2 before surgical treatment were 25.8 ± 5.7 pg/ml, after surgical treatment, they decreased to 13.5 ± 5.3 pg/ml. The detailed analysis of patients in the main group showed that the level of prostaglandin E2 did not differ statistically in different erosive forms of esophagitis, or CLE and NERD. But it is statistically different from the level of prostaglandin E2 in practically healthy individuals of the control group. The conducted correlation analysis indicated that the level of prostaglandin E2 did not depend on the duration of acid exposure in the esophagus, as well as on the severity of esophagitis or the presence of CLE. Conclusions. With effective surgical treatment of gastroesophageal reflux disease, a decrease in the level of prostaglandin E2 after surgery is determined compared to preoperative data to the level obtained in a group of practically healthy patients. The obtained dynamics of the level of prostaglandin E2 indicates the possibility of this hormone influencing the tone of the lower esophageal sphincter and active participation in the pathogenesis of GERD, which confirms the possibility of its use as an additional diagnostic marker of inflammation in the esophagus and a marker of the effectiveness of surgical treatment.