BackgroundTraumatic stress is a global mental health problem requiring novel, easily implemented treatment solutions. We compared the effectiveness and efficiency of Reconsolidation Therapy (RT) to the well-established antidepressant paroxetine, in reducing symptoms of traumatic stress among patients from Nepal, a low-income country.MethodsForty-six adults with posttraumatic stress disorder (PTSD) were randomized to one of two groups. The reconsolidation blocker propranolol was administered 90 min before briefly recalling a traumatic memory with a therapist, weekly for six consecutive weeks. This was compared to daily paroxetine for 26 weeks. Self-reported PTSD symptoms were assessed blindly at the 7th, 13th, and 26th weeks.ResultsAn intent-to-treat analysis revealed a robust pre- to post-treatment main effect (β1 = − 4.83, 95% CI = [− 5.66, − 4.01], p < .001), whereby both groups improved, with Cohen’s effect sizes of d = 2.34 (95% CI = [1.57, 3.12]) for paroxetine, and of 2.82 (95% CI = [1.98, 3.66]) for RT after 7 weeks, suggesting treatment effectiveness for both groups in a real-world setting. Three and six-month follow-up yielded further significant improvement in both groups, which did not differ from each other.ConclusionRT also displayed promising efficiency, considering that it had been discontinued weeks earlier while the paroxetine treatment was continued, as recommended. RT could be taught in low-income countries as part of the local therapeutic resources to treat the core symptoms of PTSD, provided that such results are replicated on a broader scale.Trial registrationISRCTN34308454 (11/10/2017).