As more skilled cancer support group leaders create better outcomes for group members, it is important to provide training for this population. The aim of this randomized controlled trial was to evaluate the effect of a low resource demanding (LRD) versus a high resource demanding (HRD) intervention. Leaders were randomized to receive either an LRD (access to a website and discussion forum only) or an HRD intervention (access to the website and discussion forum, DVD, and manual, plus a 2-day training workshop). Pre- and postintervention assessment was conducted using 3 standardized measures. Sixty-five leaders (HRD n = 35; LRD n = 30) participated, with postintervention data collected from 54 leaders (83%). Pre- and postintervention, leaders reported low levels of challenge and high levels of psychological well-being and confidence. Comparative analysis revealed no significant group differences (all p > .05). However, in semistructured interviews (n = 12) and focus groups (n = 8), leaders reported that training had positive effects, despite barriers to intervention use.