There is still a lack of indicated prevention programs for couples who, although subjectively concerned about their relationship, do not seek marital therapy. In a previous randomized controlled study, the efficacy of a cognitive-behavioural psychoeducational program delivered on a weekend by two trainers for groups of four couples was established. The program consists of communication and problem-solving training, couples' discussions to clarify their relationship expectations, and exercises to enhance their sensual/sexual relationship. In the current study, the effectiveness of adding two booster sessions with each couple individually one and three months after the weekend training program was investigated. Sixty-two couples were recruited by newspaper announcements. At post assessment, couples emitted significantly more positive and less negative verbal and nonverbal communication behaviours during a conflict discussion task than at pre-assessment, thus replicating the previous findings. At the 1-year follow-up, couples with booster sessions reported significant higher marital satisfaction ratings and fewer problem areas than couples receiving the weekend program only. Booster sessions seem to be effective in enhancing the long-term effectiveness of preventive interventions.