Background <p>Teaching Recovery Techniques (TRT) is a brief psychosocial intervention designed to reduce symptoms of post-traumatic stress among children. To strengthen the evidence base for TRT, a nationwide multisite cluster RCT of TRT with accompanied refugee children was planned in Sweden, including an internal pilot with the primary objectives of assessing screening, recruitment, attendance, and retention. Secondary objectives were to consider the feasibility of randomisation, the suitability of the questionnaires employed in the main RCT, and intervention acceptability.</p> Methods <p>Accompanied refugee children aged 8 to 17&#xa0;years, who arrived in Sweden within the last 5&#xa0;years and screened positive for symptoms of post-traumatic stress, were allocated to the intervention or waitlist arm using non-blinded cluster randomisation. Pre- and post-measurements were conducted at baseline (T1) and after 8&#xa0;weeks (T2). Success criteria for the pilot were (i) at least 50% of those referred for participation meet the screening cut-off for post-traumatic stress; (ii) 28 eligible children recruited in the first three months; (iii) at least 50% of those randomised to intervention attending one of the five core sessions; and (iv) at least 50% of those screened at T1 complete the T2 data collection. To get a deeper understanding of the acceptability of the intervention, 11 semi-structured interviews were conducted with refugee children. The interviews were transcribed and analysed using thematic analysis.</p> Results <p>A change in recruitment strategy from referral to broader screening resulted in 44% meeting the cut-off for post-traumatic stress and, partly due to the COVID-19 pandemic, only five clusters (3 intervention, <i>n</i> = 11; 2 waitlist control, <i>n</i> = 11) were recruited over 12&#xa0;months. However, 64% of those randomised to the intervention arm attended at least one of the five core intervention sessions, and 91% were retained at T2 data collection. The qualitative inquiry confirmed the acceptability of the intervention and the need for tools to address trauma symptoms but raised concerns about stigma related to both screening and participation.</p> Conclusions <p>Although the planned RCT was deemed not feasible due to low recruitment rates, this pilot study gave insight into important practical and ethical considerations. Adjustments to information, screening, and recruitment may improve the likelihood of a successful RCT. Adopting a strength-based approach when introducing a mental health intervention to refugee children is recommended; not only may this reduce stigma, but it may actively shift from a deficit-focused discourse.</p> Trial registration <p>ISRCTN17754931. Prospectively registered on 4th June 2019. <a href="https://doi.org/10.1186/ISRCTN17754931">https://doi.org/10.1186/ISRCTN17754931</a></p>