Low-intensity interventions targeting a range of mental health issues offer a scalable approach for young trauma survivors in low-middle income countries. Here, we present results from a proof-of-concept, randomized, waitlist-controlled trial evaluating MemFlex, an autobiographical memory-based intervention, for trauma-exposed Afghan youth residing in Iran. MemFlex seeks to reduce the negative and overgeneral memory biases which maintain and predict poor mental health. Young people aged 12-18 years (N = 40) with parents who had experienced forced migration from Afghanistan were recruited from high schools in Karaj City in Iran. All had experienced a traumatic event in the last year. Participants were randomized to receive four weeks of a group-based delivery of MemFlex or Waitlist. Our primary cognitive outcome was autobiographical memory flexibility, that is, the ability to deliberately retrieve any memory type on demand. Primary clinical outcome was emotional distress, measured on the Farsi version of the Hopkins Symptom Checklist. Results indicated that MemFlex participants demonstrated large effect sizes for pre-to-post improvement in memory flexibility (d = 2.04) and emotional distress (d = 1.23). These improvements were significantly larger than Waitlist (ds < .49), and were maintained at three-month follow-up. Positive benefits were observed for completion of MemFlex, and future comparison against an active intervention appears warranted. Further evaluation of MemFlex in this context may offer a low-cost, and low-resource intervention to improve access to psychological intervention for young migrants in low-middle income countries.