HIV disproportionately affects blacks more than other groups in New York City (NYC) as well as nationally. Partner Services (PS) are a proven way to interrupt HIV transmission. In NYC, PS outcomes are worse among blacks compared to other race/ethnic groups. We compared PS outcomes by country of birth to identify opportunities for improved PS effectiveness. We assessed number of sex and needle-sharing partners elicited, notified, and HIV tested, as well as number of newly identified HIV cases and number of interviews needed to identify a new HIV case. Between July 2006 and December 2008, 1049 African Americans, 285 Caribbean-born blacks, and 168 African-born blacks were interviewed for HIV Partner Services. African Americans, Caribbean-born blacks, and African-born blacks had average age of 38, 37, and 43 years and 10.0%, 0.4%, and 0.6% reported intravenous drug use, respectively. All groups had a high proportion of cases with an AIDS-defining CD4 count at HIV diagnosis (30.8%, 34.5%, and 47.9% for African Americans, Africans, and Caribbeans, respectively). The number needed to interview to find one newly diagnosed HIV case was high for all groups (66, 57, and 56 among African Americans, Africans, and Caribbeans, respectively), indicating all had similarly low rates of new HIV case identification. NYC blacks and their partners are benefiting from current Partner Services outreach as PS did identify new HIV cases among partners from all 3 groups. However, further work is needed to improve HIV case finding from Partner Services in these groups, and additional measures to promote early diagnosis are needed.