To improve rates at which physicians provide cancer control procedures, it is first necessary to identify physician and environmental characteristics that explain variations in those rates. This study used an attitude-behavior model as a guiding framework to identify beliefs, sources of influence, facilitating conditions, and critical events that may be important determinants of physicians' rates for providing eight cancer control activities. Open-ended, semistructured interviews were conducted with 26 family physicians to discuss the factors that may have affected their policies for providing each of the eight cancer control activities. Content analysis of those interviews produced unique lists of beliefs, sources of influence, facilitating conditions, and critical events for each activity. These lists of factors are more comprehensive than those identified in previous studies. A questionnaire has been developed based on these findings, and a validation study is being conducted to identify the factors that best explain variation in rates at which cancer control activities are performed.