A study evaluated a training-of-trainers strategy to update HIV/AIDS knowledge and improve attitudes and behavior among health professionals and the public. A survey was carried out among health workers and villagers. An initial workshop was given to 55 staff from several health institutions. Trainees were provided limited funds to conduct secondary workshops at local levels. They were requested to diffuse knowledge to patients during routine health visits. A follow-up survey was conducted 18 months later in counties in which workshops were not held. Knowledge, attitudes, and behavior were compared both at the baseline and follow-up surveys, and before and after the intervention. Nearly 95% (94.8%, or 13,782) of health workers in Fuyang Prefecture were trained secondarily at local levels. Knowledge was significantly higher in intervention (88.5-99.8%) compared with nonintervention (37.4-53.7%) counties, and after intervention (22.2-66.6%), respectively (p < .01). Attitudes toward people with HIV/AIDS improved significantly in intervention counties. Condom use during last sexual intercourse increased from 11.0% to 33.5% in health workers (p < .01) and from 8.7% to 18.5% among villagers (p <.01). The strategy wascost effective for improving knowledge and attitudes and promoting condom use.