Background <p>Children growing up in families experiencing complex and multiple problems face an increased risk of interpersonal trauma and adverse developmental outcomes. Parental trauma, emotion regulation difficulties, and strained parent-child relationships may limit the feasibility and response to outpatient trauma-focused interventions. To address these barriers, the Dutch KINGS program integrates trauma treatment for parents and children with work on family interactions and parenting in an inpatient setting that provides safety and structure.</p> Objective <p>We examined outcome trajectories and change patterns before, during, and after KINGS across child and parental trauma symptoms, child emotional and behavioral problems, parental feelings and responses toward the child, and the parent-child relationship.</p> Method <p>We conducted a quasi-experimental multiple-case time-series study with non-concurrent, staggered intervention onset. The analytic sample included 15 families (<i>n</i> = 15 parents; <i>n</i> = 18 children) who completed weekly assessments across baseline (≥ 5 weeks), intervention, and 8-week follow-up. We used visual analyses, Simulation Modeling Analysis (SMA), and Nonoverlap of All Pairs (NAP) to evaluate changes and temporal patterns.</p> Results <p>For each outcome, except the parent-child relationship, at least half of the participants showed moderate-to-strong improvement during KINGS. Change patterns varied (e.g., gradual gains or brief early worsening followed by improvement), and most gains were maintained or enhanced during follow-up. Improvements were most consistent for child and parental trauma symptoms.</p> Conclusions <p>Integrative, inpatient trauma-focused family treatment was associated with improvements in families for whom outpatient care proved insufficient. Larger comparative studies with extended follow-up are needed to strengthen causal inference and assess generalizability.</p>