To better address prostate cancer disparities, we investigated the differences among US-born, African-born, and Caribbean-born Black men on prostate cancer risk reduction and early detection behaviors. Data were collected from over 3,400 Black men in five cities in Florida. One-way analysis of variance was used to explore the ethnic variations among the three study groups. We found that there were significant differences among the three groups. The US-born Black men had the highest knowledge, were most likely to have health insurance, and consume the most meat compared to African-born, and Caribbean-born Black men. African-born Black men were most likely to use chemoprevention products and discuss prostate cancer risk-reduction and early detection with a physician. Given the significant number of foreign-born Blacks in the US, it is important to disaggregate the data of US-born and foreign-born Blacks to develop effective programs and policies to address the needs of each group.