Sexual intimacy and loneliness are significant components influencing the quality of marital relationships. Loneliness can negatively affect couples' ability to establish deep emotional connections, potentially leading to emotional distancing. In contrast, sexual intimacy plays a vital role in psychological well-being, individual health, and marital adjustment, and its enhancement can improve the quality of marital life and increase marital satisfaction. This study aimed to examine the effectiveness of a marital enrichment intervention based on the Gottman model. The research employed a quasi-experimental design with pre-test, post-test, and follow-up, including a control group. The statistical population consisted of married couples in Isfahan, Iran, selected through voluntary sampling and randomly assigned to two equal groups. The experimental group participated in eight 90-minute sessions of marital enrichment training, while the control group only completed the research questionnaires during the pre-test, post-test, and follow-up phases. Data were analyzed using repeated measures multivariate analysis of variance. The results indicated that the intervention significantly increased sexual intimacy (F = 5.53, p < 0.05) and decreased feelings of loneliness (F = 41.76, p < 0.05), with the effects remaining stable after a two-month follow-up.