Impaired right ventricular (RV) function has been reported to occur in patients with HIV when studied by echocardiography. However, for accurate evaluation of RV function and morphology, first-pass radionuclide ventriculography (RNV) and cine magnetic resonance imaging (cine-MRI) are methods of choice. Studies of RV involvement in patients with HIV are of interest since pulmonary hypertension is a known serious complication of HIV recognized with increasing frequency. The aim of the present study was to characterize cardiac function and geometry in patients with HIV and reduced right ventricular ejection fraction (RVEF). To do so, we screened patients with RNV and performed an additional cine-MRI in those with reduced RVEF determined by RNV. Ninety patients with HIV were included. To evaluate the MRI measures exactly we included 18 age- and gender-matched healthy volunteers to establish reference values. RNV showed in 13 of the 90 patients a reduced RVEF with a standard cutoff value for RVEF of 0.50. Six of these agreed to have an additional MRI investigation performed. These 6 patients with HIV had an RVEF measured by RNV between 0.41-0.49. Measured by MRI the range of RVEF was 0.47-0.55 with 3 below the lower 95% reference limit according to the control group (lower reference limit: 0.49). None of the 6 patients with HIV had dilated right ventricle and only 1 had a marginally increased right ventricular mass index of 43 g/m2 (reference: <41 g/m2). With use of MRI, a few patients with HIV may have a marginally reduced RVEF but normal RV dimensions and mass. Thus, RV dysfunction does not seem to constitute a major clinical problem in this antivirally treated HIV population.