The effectiveness of a group intervention program to reduce psychological problems in relatives living with patients with severe mental disorders was evaluated. Attended eight mothers and one father whose adult children were receiving treatment in a Mental Health Day Hospital. They followed the Beck Anxiety Inventory, the Beck Depression Inventory-II, the Perceived Stress Scale, the SF-36 Health Survey, the Coping Strategies Inventory, and the Assertiveness Inventory. They attended 20 sessions of group psychological acceptance and development of skills-based treatment. Following the completion of the program, the level of depression in the parents decreased significantly, assertive conduct increased, as did the use of coping strategies aimed at the solution of problems. The relatives rated the program as useful, applied what they have learned to their daily lives, decreased the levels of psychological discomfort, and the majority applied what they have learned to what they value most. Concluding the program was successful in decreasing depression among patients’ relatives and in increasing their adaptive coping skills. Nevertheless, more studies are needed in order to overcome some limitations such as the size of the cohort and the lack of a control group.