Rates of referral of patients to psychosocial services are low in most cancer treatment centers, while rates of distress are high. The purpose of this study is to identify clinicians' barriers to referring cancer patients to psychosocial services and strategies that could increase rates of referral. A purposive sampling method ensured data were gathered in two large public teaching hospitals from seven oncologists and five hematologists with varying levels of experience, of whom five were female. Data were collected using semistructured interviews guided by the Capability, Opportunity, Motivation and Behavior model (Michie S, Atkins L, West R. The Behaviour Change Wheel: A Guide to Designing Interventions. United Kingdom: Silverback Publishing; 2014.). This helped us to identify modifiable variables associated with referral likelihood and associated evidence-based strategies using the Behavior Change Wheel. Data were analyzed using Thematic Analysis. Barriers relating to capability, opportunity, and motivation to refer to psychosocial services were identified, including lack of knowledge of available services, how to refer to them, and the types of patients who would benefit. Other barriers included the following: lack of time to discuss and refer, convoluted referral pathways, long waiting times, and fear of patient reluctance due to stigma. Respondents identified numerous strategies for overcoming barriers, including training on referral best practice, role-plays, the provision of lists of services with referral and contact details, and increasing service capacity via additional funding. Findings inform the development of acceptable, evidence-based strategies, to improve rates of referral to psychosocial services by oncologists and hematologists. Without implementation, a substantial number of people affected by cancer will continue to suffer from potentially treatable distress.