BACKGROUND: Interventions to cope with emotional states (depression, stress, and anxiety) and strengthen attachment are important. This research aims to determine the effect of the Mindfulness-Based Childbirth and Parenting Program (MBCP) on pregnant women's prenatal attachment and their levels of depression, stress, and anxiety. METHODS: This randomized controlled trial included 36 participants who were randomly assigned into two groups: the Mindfulness-Based Childbirth and Parenting Program (MBCP) group (18 participants), and the control group (18 participants). The Depression Anxiety Stress Scales-21 (DASS-21) and the Prenatal Attachment Inventory (PAI) were administered at the beginning of the study and again 8 weeks later. RESULTS: In the follow-up, the MBCP group exhibited significantly higher mean scores on the PAI compared to the control group (p <
0.05). The interaction between group and time was significant for PAI scores (F = 15.979, p <
0.001). When comparing the scores of the DASS-21 between the MBCP and control groups at the follow-up, the MBCP group showed significantly lower median stress scores compared to the control group (p <
0.05). There was no statistical difference between the baseline and follow-up median scores for depression, anxiety, and stress in the control group in terms of within-group comparison (p >
0.05). However, there was a statistical difference between the baseline and follow-up scores for depression, anxiety, and stress in the MBCP group in terms of within-group comparison (p <
0.05). CONCLUSION: This study has demonstrated that the MBCP program has positive effects on prenatal attachment, anxiety, depression, and stress. Therefore, it is considered that MBCP could be a tool for nurses, midwifes, child development specialists, and other healthcare professionals. CLINICAL TRIAL REGISTRATION NUMBER: NCT05866549.