Purpose <p>To evaluate the relationship between dyadic coping, intimate relationship, and reproductive concerns of breast cancer women of reproductive age and identify the mediational role of the intimate relationship in linking dyadic coping and reproductive concerns.</p> Methods <p>This descriptive cross-sectional study enrolled only breast cancer patients aged 18–44&#xa0;years. Finally, 296 participants aged 24–44 (38.38 ± 4.14) years were recruited. They completed the general information questionnaire, the Dyadic Coping Inventory, the Marriage Adjustment Test, and the Reproductive Concerns After Cancer Scale. Spearman correlation analysis was conducted to validate the association between study variables. The structural equation model was performed to confirm the hypothesized mediation model.</p> Results <p>This study revealed that both dyadic coping (<i>r</i> = − 0.579, <i>P</i> &lt; 0.001) and intimate relationship (<i>r</i> = − 0.670, <i>P</i> &lt; 0.001) reported significantly negative concerning reproductive concerns. In contrast, dyadic coping was positively related to intimate relationship (<i>r</i> = 0.818, <i>P</i> &lt; 0.001). Additionally, our results confirmed that intimate relationship was a mediator of the relation between dyadic coping and reproductive concerns (indirect effect = − 0.543, 95% confidence interval, − 0.719 to − 0.382).</p> Conclusion <p>Dyadic coping can impact patients’ reproductive concerns through the intimate relationship, which should be considered a target for intervention. Health professionals should concentrate on implementing couple-based interventions to increase the level of dyadic coping and improve the intimate relationship between couples, which will reduce the level of reproductive concerns in patients.</p>