The proportion of tuberculosis (TB) cases among foreign-born persons in the United States has increased steadily, accounting for half of reported cases in 2001 for which country-of-origin information was available. During 1998-2001, the annual number of TB cases among African immigrants and refugees in Seattle and all of King County increased approximately threefold to that during 1993-1997. This report summarizes the investigation of cases during 1998-2001 and outlines the public health interventions implemented to prevent TB in this population. The findings indicate that in Seattle-King County, persons at risk for TB who have arrived recently in the United States were primarily from the African-Horn countries of Eritrea, Ethiopia, and Somalia. Primary health-care providers and civil surgeons (i.e., physicians appointed by the Immigration and Naturalization Service to screen for medical conditions as required for changes of immigration status) should be aware of the high TB rate among African immigrants, especially within the first 5 years after immigration, and be alert for severe extrapulmonary forms of TB.