BACKGROUND: Accurate measurement of mental health disorders in conflict-affected populations is crucial for improving mental health care for these populations. Most studies to develop mental health questionnaires for conflict-affected populations are conducted in high income countries despite the vast majority of conflict-affected populations residing in Low and Middle Income Countries (LAMICs). The aim of this systematic review is to assess the quality of questionnaires for mental disorders that have been either developed or validated in conflict- affected settings in LAMICs. METHODS: A systematic review of 5 databases (CINAHL Plus, EMBASE, Global Health, MEDLINE and PsycINFO) was conducted to identify validation studies for questionnaires measuring mental health disorders in adult conflict-affected population in LAMICs. Well-established psychometric criteria evaluating reliability, validity and responsiveness of questionnaires were applied for quality appraisal. RESULTS: Thirty validation studies were included in this review, which reported on data for 33 questionnaires. Twenty-four were questionnaires that had been originally developed in different settings and adapted for use with a new conflict-affected population and 9 had been newly developed for the conflict-affected population being studied. Overall, there was high variability in the quality of evidence for the questionnaires with moderate evidence for the validity and reliability of included questionnaires but no responsiveness data reported. CONCLUSION: There has been increasing recognition of the particular importance of psychometrics in this field to facilitate the development of good quality mental health questionnaires suitable for use in LAMICs. However, this review highlighted the current limited quantity and quality of such questionnaires.