Despite recommendations of annual HIV testing for high-risk individuals, one-third of infected men who have sex with men (MSM) are unaware of their serostatus. In an effort to improve HIV prevention services and subsequently decrease prevalence, this study aimed to examine the HIV testing patterns and factors associated with testing frequency among MSM. Utilizing eight reliable and validated instruments and a sample of 374 sexually active MSM, this study examined a series of demographic, behavioral and psychosocial associations of antibody testing frequency, including substance use/abuse, depression levels, internalized homophobia, unprotected anal intercourse, sexual regulation and attribution, and HIV knowledge, . MSM who tested for HIV frequently were more likely to be older, have higher levels of educational attainment, and self-identify as gay. Respondents who reported never having been tested and irregularly tested had higher levels of internalized homophobia, depression, and alcohol use and abuse patterns. Respondents who had never been tested or infrequently tested engaged in lower levels of sexual risk, particularly unprotected receptive anal intercourse. Those with no or irregular histories of testing also exhibited greater external sexual loci of control, and were significantly more likely to attribute life events to external, unstable, and pessimistic causes.