Leaders of intervention groups for batterers must continuously assess how well they are meeting their goal of reducing violence. This article reports on survey and qualitative interview data from group leaders about their risk assessments. The practitioners were aware that their information about the risk levels of members was limited. They usually chose the middle of risk scales and reported moderate confidence in their predictions. Group leaders became increasingly confident in their risk predictions over an 8-week period, while they also predicted greater likelihood of physical abuse. This research supports the need for collaboration between practitioners and researchers to increase group leaders' skills and confidence in risk assessment, especially in the early stages of group interventions. Abstract published by arrangement with Taylor and Francis.