Since the introduction of highly active antiretroviral therapy there has been a marked increase in the prevalence of HIV associated neurocognitive disorders (HAND). It has been suggested that higher levels of physical fitness are associated with higher levels of cognitive function in people living with HIV (Dufour et al. 2011). Furthermore, evidence from other clinical areas suggests that higher levels of physical fitness are associated with improved cognitive function(Erickson et al 2011; Suzuki et al 2013). . This project aimed to investigate whether a 16 week exercise intervention could improve cognitive function in people with HIV. Thirteen participants were recruited from a pre-defined group of patients who had been previously screened for HAND in St. James’ Hospital, Dublin. Participants were randomised into two groups: an exercise group (n=6), that completed a 16 week supervised aerobic exercise programme training 2 to 3 times per week, and a control group (n=7) that received no intervention and continued with their routine care. Primary outcomes measured included cognitive function (Montreal Cognitive Assessment (MOCA) and the trail making tests A and B), aerobic fitness (modified Bruce protocol), sleep quality (Pittsburgh Sleep Quality Index; PSQI), metabolic profiles and anthropometrics. Higher levels of moderate physical activity and aerobic fitness were significantly correlated with higher cognitive function at baseline (P=0.04 and P=0.001 respectively). Despite an overall low adherence rate of 60% to the exercise programme, there was a tendency for a numerically larger improvement in short term memory in the exercise group compared to the control group. However, there were no significant improvements in global cognitive scores. In addition, significant improvements were recorded in daytime dysfunction, an important domain of sleep quality, in the exercise group following training compared to the control group (P<0.05). No significant improvements were seen in aerobic fitness or metabolic profiles after the intervention. In conclusion exercise may have beneficial effects on cognitive function and sleep quality in people with HIV. However, further research is warranted with larger sample sizes and adherence rates to allow for a more in depth investigation of the effects of exercise on cognitive function in this population.