This study examines the impact of direct-to-consumer (DTC) pharmaceutical advertising on prescription drug knowledge and the requesting behavior of consumers. The authors developed and tested a conceptual model of prescription drug knowledge and requests. Consumers' belief that drug advertising can educate them was associated with a greater amount of drug knowledge, and the belief they would upset physicians by asking for specific drugs was associated with less knowledge. The belief that drug advertising reduces prices was associated with greater probability of drug requests, and the belief that physicians should be the sole source of drug information was associated with lesser probability of request. Preference for generic drugs was associated with a lesser likelihood of requesting a specific drug. Media exposure and drug advertising awareness were associated with higher drug knowledge and a greater probability of drug requesting.