Background Access to evidence-based psychological treatments for common mental health disorders remains limited in low-resource settings. This pilot randomized controlled trial evaluated the feasibility and acceptability of the Urdu Adapted Unified Protocol (UA-UP), a transdiagnostic cognitive-behavioral intervention for anxiety and depression, in Pakistan, and explored preliminary clinical outcomes.Methods 51 adults meeting diagnostic criteria for anxiety and/or depressive disorders were randomized to a 14-week UA-UP intervention (n = 25) or a waitlist control (n = 26). Feasibility was assessed through recruitment, retention, and adherence rates. Acceptability was evaluated via session attendance, homework completion, participant satisfaction (CSQ-8), and qualitative feedback. Clinical outcomes (anxiety, depression, emotion regulation, and functional impairment) were assessed using validated measures. Between-group differences were analyzed using repeated-measures general linear models, and 95% confidence intervals were reported.Results Feasibility indicators were high, with recruitment (85.7%), retention (82.4%), and strong session adherence. Acceptability was supported by 79% homework completion and high satisfaction (mean CSQ-8 = 29.65, SD = 2.60). Participants in the UA-UP group demonstrated greater improvements in anxiety, depression, and functional impairment compared to the control group, with large effect size estimates (e.g., anxiety g = 1.18; depression g = 1.15). Qualitative findings indicated enhanced emotional awareness, improved coping, and strong engagement with culturally adapted content.Conclusions The UA-UP demonstrated high feasibility and acceptability as a culturally adapted transdiagnostic CBT intervention in Pakistan. These findings support the conduct of a fully powered randomized controlled trial to evaluate clinical effectiveness and inform scalable implementation in low-resource settings.Trial Registration ClinicalTrials.gov, NCT06002087. Registered 03 August 2023 (retrospectively registered).