This article reports the results on marriages of a randomized clinical trial for couples experiencing the transition to parenthood. In addition to a control group, there was 1 intervention, a psycho-communicative-educational 2-day couples’ workshop. The outcome measures were marital quality, postpartum depression, and expressed hostile affect (assessed using an observational coding of marital conflict discussions videotaped in couples’ homes). Data were collected at 3 time points: before the intervention in the last trimester of pregnancy, when the baby was 3 months old, and when the baby was 1 year old. Results showed that, in general, the preventive intervention using a psycho-communicative- educational format was effective compared to a control group for wife and husband marital quality, for wife and husband postpartum depression, and for observed wife and husband hostile affect scored from videotapes of marital conflict. (Author abstract).