Since the advent of highly active antiretroviral therapy (HAART) in 1996, progression from receiving diagnosis of human immunodeficiency virus (HIV) infection to having acquired immunodeficiency syndrome (AIDS) has slowed substantially, making HIV-transmission patterns less predictable through AIDS surveillance alone. Consequently, CDC has recommended that states report diagnoses of HIV infections in addition to cases of AIDS. Recent estimates of HIV diagnoses suggested a leveling of the downward trend in HIV infections nationally and increases in HIV infections among certain populations. Reports of syphilis outbreaks and increased unprotected sex raised concerns regarding increases in HIV transmission among men who have sex with men (MSM). In response to these developments, CDC analyzed trends in HIV diagnoses in 29 states that conducted name-based HIV/AIDS surveillance during 1999-2002. This report summarizes the results of that study, which indicated that HIV diagnoses increased among men, particularly MSM, and also among non-Hispanic whites and Hispanics. The findings emphasize the need for new prevention strategies to reverse potential increases in HIV transmission among these populations.