The purpose of this study was to evaluate the effects of a relationship enhancement education and counseling (REEC) program on improving middle-aged couples' marital intimacy. The randomized controlled trial study was conducted in Tabriz, Iran, from May to December 2017. Thirty-two married couples, attending a public health center and meeting the inclusion criteria, were randomly assigned to the intervention (receiving REEC) and control (receiving routine care) groups. The outcome measures were marital intimacy, sexual motivation, and sexual function. Data were collected at three points in time. The Statistical Package for the Social Sciences was used for the purpose of data analysis. In all analyses, the interventional group outperformed the control group on all outcome measures. In the intervention group, results showed statistically significant improvement in all variables of interest after one week and 12 weeks in comparison with preintervention. Upon the completion of the experimentation, it can be concluded that a REEC program positively affects marital intimacy, sexual function, and sexual motivation in middle-aged couples.