Cancer affects a significant number of people and their families. In addition to physical symptoms, people with cancer experience considerable levels of psychosocial distress. Psychosocial oncology has been developed to address this distress. In this meta-analysis, psychosocial interventions for adults with cancer were systematically reviewed. A central finding was the dearth of clinical trials published by social work researchers and clinicians. Small intervention effects were noted for some psychosocial interventions, particularly those in which a focus on stress and coping were included; however, the poor quality of reporting negated conclusive results. The synthesis of research conducted and reported with methodological rigor may inform social work practice, with the ultimate goal of improving the quality of patient care and the quality of patient outcomes. The implications for social work clinicians and researchers are discussed.