["Child &Family Social Work, Volume 31, Issue 2, Page 1219-1229, May 2026. ", "\nABSTRACT\n\nThis study evaluates the effectiveness of a short‐term, solution‐focused group intervention designed to support the psychosocial development of children living in residential care. The intervention was implemented under the leadership of a psychiatric nurse in close collaboration with a social worker, providing rare experimental evidence on interdisciplinary practice and offering an original contribution to the field of social work. The study was designed as a randomized controlled trial with a pre‐test–post‐test control group design. The sample consisted of 57 children residing in state‐run residential institutions who were randomly assigned to an intervention group (n = 29) or a control group (n = 28). The intervention comprised six group sessions structured in accordance with the core principles of solution‐focused therapy. Data were collected using the Children’s Hope Scale and the Social Skills Scale and were analysed using nonparametric statistical tests. Following the intervention, a statistically significant increase in children’s hope levels was observed (p < 0.05), whereas improvements in social skills approached but did not reach statistical significance (p = 0.054). Effect size analyses indicated a moderate effect on hope (Cohen’s d = 0.56) and a small effect on social skills (Cohen’s d = 0.27). These findings suggest that solution‐focused interventions are effective in enhancing children’s hope, while the development of social skills may require longer‐term or more comprehensive and context‐sensitive interventions commonly addressed within child welfare and social work practice. Overall, the study demonstrates that a short‐term solution‐focused group intervention implemented within a child welfare framework through close collaboration between social work and psychiatric nursing leads to meaningful improvements in children’s hope levels. Although short‐term gains in social skills were limited, the findings underscore the value of interdisciplinary, social work‐led intervention models that integrate strengths‐based and participation‐oriented social work practice with the therapeutic contributions of psychiatric nurses, offering a practice‐oriented, evidence‐based, and original approach to advancing psychosocial support for children living in institutional care.\n\n\nTrial Registration\nClinicalTrials.gov identifier: NCT07135908.\n\n"]