SETTING Haiti has the highest burden of tuberculosis (TB) in the Americas, with an estimated prevalence of 254 per 100 000 population. The Haitian Group for the Study of Kaposi's Sarcoma and Opportunistic Infections (Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes, GHESKIO) conducted active case finding (ACF) for TB at the household level in nine slums in Port-au-Prince. OBJECTIVE We report on the prevalence of undiagnosed TB detected through GHESKIO's ACF campaign. DESIGN From 1 August 2014 to 31 July 2015, we conducted a retrospective cohort analysis using GHESKIO's ACF campaign data. All individuals who reported chronic cough (cough 2 weeks) were tested for TB at GHESKIO, and those aged 10 years were included in the analyses. RESULTS Of 104 097 individuals screened in the community, 5598 (5%) reported chronic cough and satisfied the study inclusion criteria. A total of 1110 (20%) were diagnosed with active TB disease (prevalence of 1066/100 000). Of the 5472 (98%) patients tested for human immunodeficiency virus (HIV), 528 (10%) were HIV-positive; 143 (3%) patients were diagnosed with both diseases. CONCLUSION Household-level screening for cough with TB and HIV testing for symptomatic patients was a high-yield strategy, leading to the detection of a prevalence of undiagnosed disease exceeding national estimates by more than four-fold for TB, and by five-fold for HIV.