Patient electronic personal health record (PHR) use has been associated with improved patient outcomes in diabetes and depression care. Little is known about the effect of PHR use on HIV care processes and outcomes. We evaluated whether there was an association between patient PHR use and antiretroviral adherence. Data came from the Veterans Aging Cohort Study and included cross-sectional survey and medical record data from 1871 HIV+ veterans. Our adherence measure was an antiretroviral medication possession ratio, dichotomized at 0.90, and based on pharmacy refill data. In our sample 44 % did not use the internet, 14 % used internet but not for health, 27 % used internet for health but not the PHR, and 14 % used the PHR. In multivariable analysis PHR use was associated with >/=90 % adherence after controlling for socio-demographic variables. Findings provide support for longitudinal studies and studies that identify which PHR functions (e.g. online medication refills, viewing lab results, secure messaging with providers) are most closely associated with medication adherence.