This research aims to evaluate the effectiveness of a responsive early intervention program to build up the parenting skills of foster and adoptive mothers with children 0-24 months. The present study employed the unification/variation-based design by adding the pretest post-test nonequivalent group intervention (experimental) advanced design. Both quantitative and qualitative data are collected and analyzed in parallel but independent of each other, and the final results are interpreted conjunctly. 30 mothers and children, including 5 foster mothers, 5 foster children, 5 adoptive mothers, 5 adopted children, 5 biological mothers, and 5 biological children, participated in the study. In order for all foster and adoptive mothers and children reached during this process to be included in the intervention, a control group was not formed, but two intervention groups were determined as the foster mother intervention group and the adoptive mother intervention group. In addition, aiming to compare the intervention groups with an independent group at the post-test stage, 5 biological mothers and children with similar characteristics were also included in this study. In the present study, to collect quantitative data, "Parent Infant Play Observation code," "Resilience Scale for Adults," "Child Perspective Assessment Tool," and "Mother-Infant Interaction Checklist" were used. To collect qualitative data for interviewing, "Semi-structured interview forms" and for observing "Researcher Diary" and "Development Observation Reports" were employed. Results were analyzed under six themes, including foster and adoptive mothers' childhood understandings, resilience skills, parent-infant play behaviors, interactions, observations of children's development, and general views on education. Accordingly, regarding the understanding of childhood, a significant difference has been observed between the pretest and post-test scores in belief in the nature of the child. Participants also expressed their views reflecting the belief in the nature of the child. Regarding resilience, a significant difference has been found between the pretest-posttest scores of self-perception, social resources, and the scale in general. Participants mentioned positive developments in their social and family lives in the interviews taken after the intervention. Furthermore, they stated that the received intervantion calmed them down, relieved their anxiety, and made them feel like a conscious mother. Regarding parent-infant play behaviors, a significant difference has been observed between the pretest and post-test scores in touching, speaking, and awareness and between the pretest and post-test in interactional synchronization and body position. Participants' interactions are referred to as expressing love, hugging, calming, listening, secure attachment, feeling the baby, sustainable relationship, mutual communication, touching, and a close relationship. In addition, it has been observed that the developmental levels of children are similar to their peers. The foster and adoptive mothers expressed their general views on the intervention as follows: seeing that useful information is learned at any time; understanding that you can cope with difficult emotions; seeing the benefits that different experts bring to the intervention; a happy process; looking forward to every meeting; passing of worries; learning different information; self-development; the benefits of sharing with people in the same situation; and the feeling of falling into the void at the end of the intervention.