OBJECTIVE To study the aqueous humor dynamics in subjects with human immunodeficiency virus (HIV) with and without cytomegalovirus (CMV) retinitis. METHODS Prospective cross-sectional study. METHODS Fourteen HIV-positive subjects (27 eyes, 19 with CMV retinitis and 8 without CMV retinitis), and a control group of 9 HIV-negative subjects (17 eyes). METHODS Fluorophotometry. METHODS Aqueous flow rates as measured by fluorophotometry and intraocular pressure (IOP). RESULTS Analysis of variance of the mean corrected aqueous flow rate revealed that both HIV-positive groups had significantly lower aqueous flow rates than did the control group (P < 0.03). No difference in mean aqueous flow rates was found between the HIV-positive eyes with or without CMV retinitis. Comparison of mean IOP revealed that HIV-positive eyes with CMV retinitis had significantly lower IOP than did the HIV-positive eyes without CMV retinitis (P = 0.03) and HIV-negative subjects (P = 0.002). There was no correlation between aqueous flow rate and IOP in HIV-positive subjects (P > 0.5). CONCLUSIONS The lack of correlation between the aqueous flow rate and IOP suggests that there may be some disassociation between these parameters in HIV-positive patients. Further studies are needed to better understand the mechanism of aqueous formation and in the management of disorders affecting IOP in this population.