In this paper we report on findings from the first known study using qualitative methods to explore factors influencing physicians’ participation in an ongoing federally-funded prostate cancer chemoprevention clinical trial. We sought to identify ways to improve collaboration between researchers and physicians and enhance the success of future projects and employed purposive sampling to recruit physician/investigators who were involved or invited to participate in the trial. Using the data from open-ended semi-structured interviews, we examined patterns in their languaging and created themes. We found that individual and structural factors served as barriers and facilitators to participation. Willingness and desire to participate in the trial (individual factors) were not always enough to result in actual participation due to practice environment (structural) constraints. Our research provides a better understanding of the complex intersection of factors in this setting and through our findings we extend the theory of competing demands into the arena of prostate cancer prevention clinical trials, moving the science towards solutions to current challenges in recruitment to this type of trial. Keywords: Competing Demands, Barriers and Facilitators, Cancer, Screening and Prevention, Access to Participants, Open-Ended Semi-Structured Interviews Copyright 2014: Theresa Crocker, Karen Besterman-Dahan, David Himmelgreen, Heide Castañeda, Clement K. Gwede, Nagi Kumar, and Nova Southeastern University.