OBJECTIVES: This study assessed the impact on HIV test-seeking of North Carolina's restriction of anonymous testing to 18 of its 100 counties as of September 1, 1991. METHODS: Trends from 4 months prerestriction to the 16-month restriction period in counties retaining vs counties eliminating anonymous testing were compared. RESULTS: HIV testing increased throughout the state, but more rapidly where anonymous testing was retained than elsewhere: 64% vs 44%. These differences held for all sociodemographic subgroups and were most pronounced among adolescents and African Americans and other non-Whites. CONCLUSIONS: The data are consistent with a detrimental effect of elimination of anonymous testing, although confounding from differences in AIDS awareness or in repeat tests is possible.