The goal of this study was to examine the efficacy of minimal treatment interventions for concerned significant others (CSOs) of problem gamblers. One hundred and eighty-six participants (82% females, 56% spouses) were randomly assigned to one of three groups: the first minimal intervention group received a self-help workbook [based on behavioral principles, modified from the Community Reinforcement and Family Therapy (CRAFT) model] and the second minimal intervention group received the workbook plus telephone support. The control condition received a treatment resource information package. Overall, all participants reported significant improvement in personal and relationship functioning and gambling behavior and consequences at the 3- and 6-month follow-up. The data demonstrated differences in favor of the interventions in three areas: days gambling, satisfaction with the program, and number who had their needs met. There was no difference in the number who had entered treatment. It may be that CSOs require more guidance and follow-up support to achieve these goals using the CRAFT procedures and strategies.