AbstractOur study aims to explore the relationship between chronic hepatitis B virus (HBV) infection and the risk of gastrointestinal (GI) cancers including liver, gastric, gallbladder or extrahepatic bile duct, pancreatic, small intestine, esophageal and colorectal cancer in the Kailuan Cohort study. We prospectively examined the relationship between HBV infection and new‐onset GI cancers among 93 402 participants. Cox proportional hazards regression models, subgroup analyses and competing risk analyses were used to evaluate the association between HBV infection and the risk of new‐onset GI cancers. During a median follow‐up of 13.02 years, 1791 incident GI cancer cases were diagnosed. Compared to HBsAg seronegative participants, a significant positive association between HBV infection and GI cancers was observed in the multivariate‐adjusted models (HR 5.59, 95% CI: 4.84‐6.45). In the site‐specific analyses, participants with HBsAg seropositive exhibited an increased risk of liver cancer (HR = 21.56, 95% CI: 17.32‐26.85), gallbladder or extrahepatic bile duct cancer (HR = 14.89, 95% CI: 10.36‐21.41), colorectal cancer (HR = 1.75, 95% CI: 1.15‐2.96) and pancreatic cancer (HR = 1.86, 95% CI: 1.10‐3.99). After taking death as the competing risk event, the associations of HBV infection with the risk of these cancers were attenuated but remained significant both in the cause‐specific hazards models, the subdistribution proportional hazards models and sensitivity analyses. Our study suggests that HBV infection is associated with the elevated risk of liver cancer and extrahepatic cancer including gallbladder or extrahepatic bile duct, pancreatic and colorectal cancer among adults in Northern China.