Abstract: AIM To investigate whether a coronary calcium score (CCS) of zero by computed tomography (CT) is associated with a low risk of a significant coronary arterial luminal narrowing. METHODS We performed contrast-enhanced coronary CT angiography (CTA) with a 64-sliced multidetector CT scanner in 109 Baltimore inner-city black adults aged 25 to 54 years who had a history of HIV infection, cocaine use, both, or neither, in order to determine the prevalence of noncalcified coronary plaques and stenoses. The subjects had no cardiovascular symptoms and were free of traditional risk factors for coronary artery disease (CAD). Thirty five subjects had coronary calcification. The remaining 74 participants without detectable coronary calcium were included in the analysis. RESULTS The mean age of the study population was (42.8±5.0) years and 39(35.8%) were females. The mean cholesterol level was (4.01±0.88) mmol/L. 11% of individuals without coronary calcification had coronary arterial luminal narrowing of >20%, and 7% had a stenosis ≥50%. Of the 74 participants, 59% were cocaine users, and 28% had used the drug for more than 15 years. 36.7% of the participants had taken PI. Among the variables examined, only serum HDL concentration, cocaine use, patient age, and protease inhibitors (PIs) use were significantly different between patients with and without coronary arterial stenoses. Logistic regression analyses revealed that the duration of PI use (OR=1.10) and prolonged (≥15 years) cocaine use (OR=29.6) were independently associated with the presence of coronary arterial stenoses. CONCLUSION In HIV infected patients, long-term use of cocaine and duration of combination antiretroviral therapy containing PIs may be independently associated with the presence of noncalcified coronary arterial plaques.