As part of a larger meta-analysis seeking moderators of the effectiveness of psycho-oncological interventions, this report focuses on intervention types and characteristics, including protocol components, means of delivery (mode, dose, and therapist variables), and mechanisms of effectiveness. The data set comprised 146 published and unpublished prospective controlled trials with outcomes of anxiety, depression, and distress. Analyses took into account two moderators from analysis of study design features. The authors conclude that each of the four main professional therapy types (education, relaxation, cognitive behavior therapy (CBT), and expressive-support) has effect and that it is more important to focus on participant variables, notably, elevated baseline distress. Therapy components delivered by nonprofessionals and interventions that affect the patient indirectly show potential. Recommendations for practice and research are made.