OBJECTIVE:: To assess the impact of pregnancy on mortality among HIV-infected Ugandan women initiating ART. DESIGN:: Prospective cohort study. METHODS:: HIV-infected women initiating ART in the Uganda AIDS Rural Treatment Outcomes study were assessed quarterly for self-reported pregnancy. The association between pregnancy and postpartum ('pregnancy-related') follow-up periods and mortality was assessed with Cox proportional hazards models adjusted for age, CD4 cell count, plasma HIV-1 RNA levels, and ART duration. RESULTS:: Three hundred and fifty-four women with median age 33 years (IQR: 27-37) and CD4 142â€Šcells/μl (IQR: 82-213) were followed for a median of 4.0 years (IQR: 2.5-4.8) after ART initiation, with 3 and 7% loss-to-follow-up at years 1 and 5. One hundred and nine women experienced pregnancy. Five deaths occurred during pregnancy-related follow-up and 16 during nonpregnancy-related follow-up, for crude mortality rates during the first year after ART initiation of 12.57/100 PYs and 3.53/100 PYs (rate ratio 3.56, 95% CI: 0.97-11.07). In adjusted models, the impact of pregnancy-related follow-up on mortality was highest at ART initiation (aHR: 21.48, 95% CI: 3.73-123.51), decreasing to 13.44 (95% CI 3.28-55.11) after 4 months, 8.28 (95% CI 2.38-28.88) after 8 months, 5.18 (95% CI: 1.36-19.71) after 1 year, and 1.25 (95% CI: 0.10-15.58) after 2 years on ART. Four of five maternal deaths occurred postpartum. CONCLUSION:: Pregnancy and the postpartum period were associated with increased mortality in HIV-infected women initiating ART, particularly during early ART. Contraception proximate to ART initiation, earlier ART initiation, and careful monitoring during the postpartum period may reduce maternal mortality in this setting. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.