The aim. To analyze the results of treatment of achalasia cardia by balloon dilatation with an accent on hydrodilatation, to compare the types of achalasia cardia according to high-resolution manometry with endoscopic semiotics and to evaluate the effectiveness of endoscopic balloon dilatation depending on the type of achalasia. Materials and methods. The article details an additional method of endoscopic balloon dilatation of the cardia - hydrodilatation (42 patients). The results of endoscopic balloon dilatation were analyzed according to high-resolution manometry data (37 patients). High-resolution manometry data were also evaluated in correlation with endoscopic efficacy criteria (11 patients). Results. Hydrodilatation is used as an additional method after pneumodilatation to increase efficiency of treatment (39 patients) or as an independent method (3 patients) with a combination of achalasia cardia and cicatricial changes of the esophageal-gastric junction, as well as after surgery on the cardia. The combined balloon dilatation technique gives good immediate results in 89.7% (35/39), as an independent method - 100%. Of the total number of patients, 90.5% (38/42) completed the course of endoscopic dilatation with good results, despite the fact that this is a more complex group of patients resistant to standard intervention - balloon pneumodilatation. It is not known which high-resolution manometry data should be used to assess the effectiveness of balloon dilatation: the dilatation efficiency is 75% according to the resting pressure of the lower esophageal sphincter, 83.3% according to the total relaxation pressure, 66.7% according to the cumulative analysis, strictly adhering to the reference values, and 100% according to the tendency to lower pressure. Conclusion. Endoscopic balloon dilatation is a highly effective minimally invasive method of treating achalasia cardia. Hydrodilatation is used to improve the results of endoscopic treatment. For an objective assessment of the effectiveness of balloon dilatation, high-resolution manometry should be performed before and after treatment.