IMPORTANCE Among patients infected with human immunodeficiency virus (HIV), visceral adiposity is associated with metabolic dysregulation and ectopic fat accumulation. Tesamorelin, a growth hormone-releasing hormone analog, specifically targets visceral fat reduction but its effects on liver fat are unknown. OBJECTIVE To investigate the effect of tesamorelin on visceral and liver fat. DESIGN, SETTING, AND PATIENTS Double-blind, randomized, placebo-controlled trial conducted among 50 antiretroviral-treated HIV-infected men and women with abdominal fat accumulation at Massachusetts General Hospital in Boston. The first patient was enrolled on January 10,2011; for the final patient, the 6-month study visit was completed on September 6, 2013. INTERVENTIONS Participants were randomized to receive tesamorelin, 2 mg (n=28), or placebo (n=22), subcutaneously daily for 6 months. MAIN OUTCOMES AND MEASURES Primary end points were changes in visceral adipose tissue and liver fat. Secondary end points included glucose levels and other metabolic end points. RESULTS Forty-eight patients received treatment with study drug. Tesamorelin significantly reduced visceral adipose tissue (mean change, -34 cm(2) [95% Cl, -53 to -15 cm(2)] with tesamorelin vs 8 cm(2) [95% Cl, -14 to 30 cm(2)] with placebo; treatment effect, -42 cm(2) [95% Cl, -71 to -14 cm(2)]; P = .005) and liver fat (median change in lipid to water percentage, -2.0% [interquartile range {IQR}, -6.4% to 0.1%] with tesamorelin vs 0.9% [IQR, -0.6% to 3.7%] with placebo; P = .003) over 6 months, for a net treatment effect of -2.9% in lipid to water percentage. Fasting glucose increased in the tesamorelin group at 2 weeks (mean change, 9 mg/dL [95% Cl, 5-13 mg/dL] vs 2 mg/dL [95% Cl, -3 to 8 mg/dL] in the placebo group; treatment effect, 7 mg/dL [95% Cl, 1-14 mg/dL]; P = .03), but changes at 6 months in fasting glucose (mean change, 4 mg/dL [95% Cl, -2 to 10 mg/dL] with tesamorelin vs 2 mg/dL [95% Cl, -4 to 7 mg/dL] with placebo; treatment effect, 2 mg/dL [95% Cl, -6 to 10 mg/dL]; P = .72 overall across time points) and 2-hour glucose (mean change, -1 mg/dL [95% Cl, -18 to 15 mg/dL] vs -8 mg/dL [95% Cl, -24 to 8 mg/dL], respectively; treatment effect, 7 mg/dL [95% Cl, -16 to 29 mg/dL]; P = .53 overall across time points) were not significant. CONCLUSIONS AND RELEVANCE In this preliminary study of HIV-infected patients with abdominal fat accumulation, tesamorelin administered for 6 months was associated with reductions in visceral fat and additionally with modest reductions in liver fat. Further studies are needed to determine the clinical importance and long-term consequences of these findings.