Use of complementary/alternative medicine (CAM) has been increasing, especially among patients with a chronic illness. Although asthma is the most common chronic illness affecting children in the United States, very little is known about the use of CAM in children with asthma. Our objective was to determine the prevalence and correlates of CAM use among inner-city children with asthma. A cross-sectional survey of parents of children with asthma attending an urban health center was performed. Parents were surveyed regarding CAM use over the past year, perceived efficacy of CAM, severity of child's asthma symptoms and demographic information. Differences in proportions were tested by chi-square or Fisher's exact test as appropriate. Three hundred ten parents participated, of whom 61% were Hispanic and 37% were African American. Parental mean age was 33 years and the mean age of the child was 7.2 years; 89% of parents had treated their child in the past year with some form of CAM. However, only 18% had informed a physician of doing so. The most common forms of CAM used were as follows: prayers (53%), rubs (53%), and massage (45%). Of those who used CAM, 59% perceived it to be at least as effective as pharmacotherapy, and 44% used CAM as first treatment of an asthma attack. Mild and moderate persistent asthmatics had significantly higher rates of CAM use than did mild intermittent and severe persistent asthmatics. We found a very high rate of CAM use among children with asthma in this inner-city population. Most importantly, a very high proportion of parents perceived the therapies to be effective, used them as first treatment of an acute exacerbation, and did not inform a physician of doing so. These findings have implications for the care of asthmatic children by pediatricians practicing in urban settings.