Using data collected as part of a larger evaluation of the National Cancer Institute-funded Community Clinical Oncology Program (CCOP), this paper examines the degree to which selected community, interorganizational, and structural characteristics associated with accrual to cancer treatment protocols share equal importance in accruing patients to cancer prevention and control research protocols. Analysis reveals that there are similarities in the factors that prove to be effective for accrual to both types of protocols; however, the two are not isomorphic. CCOP structure was an important predictor of treatment accrual but was not significant for cancer control accrual. Variables measuring the community health resources available to the CCOP were not significant for either treatment or cancer prevention and control research accrual when CCOP structure and interaction with participating research bases were considered. Only CCOP interaction with participating research bases was a significant predictor of both treatment and cancer prevention and control research accrual. The policy implications of these findings are discussed.