Primary Care Providers (PCPs) can be instrumental in helping to prepare patients for referral to cancer treatment. It has been suggested that PCPs can have an important impact on priming patients about the possibility of receiving care within a cancer treatment clinical trial (CCT). However, little is understood about how to effectively engage primary care providers in educating patients about trials. Data were collected as part of two qualitative research projects about primary care providers' role in referral to treatment and to CCTs. Participants were 27 PCPs who agreed to take part in qualitative face-to-face or telephone interviews and serve predominantly underserved, minority populations. Interviews identified a number of factors influencing referral to oncologists, including patients' insurance coverage, location and proximity to treatment facilities, and the strength of ongoing relationships with and/or previous experience with a specialist. PCPs overwhelmingly expressed disinterest in discussing any treatment options, including CCTs. Misconceptions about quality of care received through trials were also common, presenting a deterrent to discussion. PCPs need targeted, evidence-based educational interventions to appropriately address their concerns about cancer clinical trials, enhance provider communication skills, and alter patient referral behavior. Steps must also be taken to strengthen communication between oncologists and referring PCPs.