Oral curcumin is recognized to have anti-inflammatory properties and has been used by ancient traditional medicine for centuries to treat a variety of diseases. In vitro studies have confirmed the ability of curcumin to inhibit allergic inflammatory cytokine responses from lymphocytes; however, there are no in vivo studies of curcumin to treat inflammation associated with allergic asthma. This study was designed to determine the effect of oral curcumin supplementation on patients with stable, persistent, atopic asthma. Adult patients with stable, persistent asthma with evidence of allergic sensitization were randomized to receive 1000 mg of curcumin twice daily or placebo. Subjects were followed for 6 months and performed monthly spirometry (pre- and postbronchodilator); Asthma Control Test (ACT) scoring; and measurements for fractional excretion of nitric oxide (NO), serum eosinophil count, leukocyte count, total IgE, specific IgE to Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f), use of rescue albuterol, and dose of inhaled corticosteroid. Nine patients were randomized into the treatment arm and six were randomized into the placebo group. No differential response was seen in the treatment and placebo groups regarding the primary end point, postbronchodilator forced expiratory volume in 1 second (FEV1). Similarly, all secondary end point evaluations were not significantly different. Despite in vitro evidence that curcumin has anti-inflammatory properties and can inhibit allergic cytokine responses from lymphocytes in vitro, curcumin, 1000-mg, twice daily supplementation did not significantly affect postbronchodilator FEV1, ACT scores, use of rescue bronchodilator, dose of inhaled corticosteroid, exhaled NO, serum IgE, total white blood cell count specific IgE to Der p or Der f, and blood eosinophils in patients with persistent atopic asthma.