Gallbladder diseases, including carcinoma, are common in the northern part of India and so are Salmonella typhi infection and typhoid carrier state. This study was aimed to find out the association of typhoid carrier state in patients with cholelithiasis, carcinoma of the gallbladder, and controls. The three groups are comparable in age and sex composition. This is the first study of its kind from an area of high endemicity for both typhoid infection and carcinoma of the gallbladder. A case-control study was carried out to detect typhoid carrier state among the patients with biliary diseases and healthy controls, using indirect haemagglutination assay measuring antibodies against highly purified S. typhi Vi polysaccharide antigen. A significantly high Vi positivity was observed in patients with gallbladder carcinoma (29.4%) compared to controls (5%) (chi2 = 6.325, P < 0.004, OR = 7.19) and patients with cholelithiasis (10.7%) (chi2 = 5.066, P < 0.01, OR = 3.86). There is 8.47 times more risk of developing carcinoma of the gallbladder in culture-positive typhoid carriers than the noncarriers. The present study suggests the typhoid carrier state to be one of the possible mechanisms of gallbladder carcinogenesis.