Aim: Gastroesophageal reflux disease (GERD) occurs when the stomach contents return back to the esophagus and causes symptoms and/or complications such as reflux esophagitis (RE), Barrett's esophagus (BE) or esophageal adenocarcinoma (EAC). The transient receptor potential vanilloid subtype 1 (TRPV1) is main acid receptor, whose up-regulation plays an important role in the development of distal esophageal inflammation and reflux symptoms. The aim of this study was to analyze two functional single nucleotide polymorphisms (SNPs) in TRPV1 gene and its expression in esophageal tissue in patients with GERD. Methods: Two SNPs (C/G rs222747; C/T rs8065080) in TRPV1 gene were determined in the 325 patients with GERD (142 with RE; 61 with BE; 22 with EAC) and 101 healthy controls. The TRPV1 mRNA expression was analyzed in pathological and healthy esophageal tissues of 10 patients with RE, 8 with BE and 7 with EAC. Both types of experiments were based on TaqMan® polymerase chain reaction method. For statistical evaluation was used the Statistica v13.2 software. Results: The allele, genotype, haplogenotype or haplotype frequencies of study SNPs between patients with GERD or RE/BE/EAC separately and healthy controls were similar (p>0.05). The higher mRNA TRPV1 expression was found in the tissues of BE (p=0.017) and EAC (p=0.018) compared to healthy tissues. Conclusion: There was found increased mRNA TRPV1 expression in the pathological esophageal tissues of patients with BE or EAC who might benefit with pharmacological modulation of TRPV1 receptor.