A total of 192 HIV-1-infected antiretroviral-naive individuals had genotyping performed in our midwest university clinic between 2003 and 2005. The overall prevalence of resistance with either a reverse transcriptase or major protease mutation was 18%. There did not seem to be a significant difference in primary resistance patterns between different modes of HIV transmission (heterosexual versus men who have sex with men), gender or between white and African-American individuals.