['This study aimed to examine the effect of long-term treatment with ritonavir-boosted atazanavir (atazanavir/ritonavir) on cholelithiasis.', 'A single-centre, cross-sectional study was conducted to elucidate the prevalence of cholelithiasis in patients with HIV-1 infection who underwent abdominal ultrasonography between January 2004 and March 2013. Univariate and multivariate logistic regression analyses were applied to estimate the effects of >2 years of atazanavir/ritonavir exposure on cholelithiasis as the primary exposure.', 'Of the 890 study patients, 84 (9.4%) had >2 years of atazanavir/ritonavir exposure. Cholelithiasis was twice as frequent in those treated for >2 years with atazanavir/ritonavir [15 (18%) of 84 patients] compared with those treated for <2 years [72 (8.9%) of 806 patients] (P = 0.018). Univariate analysis showed a significant association between >2 years of atazanavir/ritonavir exposure and cholelithiasis (OR = 2.216; 95% CI = 1.206-4.073; P = 0.010) and the association almost persisted in multivariate analysis (adjusted OR = 1.806; 95% CI = 0.922-3.537; P = 0.085). Long-term treatment (>2 years) with other commonly used protease inhibitors, such as ritonavir-boosted lopinavir and ritonavir-boosted darunavir, was not associated with cholelithiasis in univariate and multivariate analysis. Additional analysis showed that >1 year of exposure to atazanavir/ritonavir was significantly associated with cholelithiasis (OR = 1.857; 95% CI = 1.073-3.214; P = 0.027), whereas >1 year of exposure to ritonavir-boosted lopinavir and ritonavir-boosted darunavir was not.'] Is cumulative exposure to ritonavir-boosted atazanavir associated with cholelithiasis in patients with HIV-1 infection?