Although most children with autism and other neurodevelopmental disorders live in low- and middle-income countries, assessment tools are lacking in these settings. This study aims to culturally adapt and validate two questionnaires for use in Ethiopia: the Autism Treatment Evaluation Checklist and the Pediatric Quality of Life Inventory™ Family Impact Module. Both questionnaires were adapted to be suitable for administration in low-literate caregivers and translated using the backward translation procedure. The factor structure, reliability and validity were investigated using caregiver-reports on 300 children with neurodevelopmental disorders or physical health conditions. Confirmatory factor analysis of the Pediatric Quality of Life Inventory™ Family Impact Module data indicated an acceptable fit of the hypothesised eight-factor structure. Internal consistency was high for both measures. Test–retest reliability was excellent for the Autism Treatment Evaluation Checklist and moderate to excellent for the Pediatric Quality of Life Inventory™ Family Impact Module. Both questionnaires demonstrated adequate known-group validity, with moderate to very large effect size group differences between case and control groups. The questionnaires correlated moderately with each other. In conclusion, the Ethiopian adaptations of the Autism Treatment Evaluation Checklist and the Pediatric Quality of Life Inventory™ Family Impact Module are valid and reliable tools for use in parents of children with neurodevelopmental disorders including autism. These adapted measures may also be valuable for use in other low-income settings. Lay abstract Although most children with autism and other neurodevelopmental disorders live in low- and middle-income countries, reliable tools to assess these conditions are often not available in these settings. In this study, we adapted two questionnaires developed in Western high-income contexts for use in Ethiopia – the Autism Treatment Evaluation Checklist and the Pediatric Quality of Life Inventory™ Family Impact Module. Both measures are completed by a child’s caregiver and both are relatively short and easy to complete. The Autism Treatment Evaluation Checklist is used to monitor the developmental issues of the child, while the Pediatric Quality of Life Inventory™ Family Impact Module measures the impact of the child’s condition on the caregiver. We translated both tools into the Ethiopian language Amharic, and adapted them to the local cultural context. Three hundred caregivers, half of whom were parents of children with neurodevelopmental disorders, and half were parents of children with physical health problems, completed the questionnaires through a face-to face interview, so that non-literate caregivers could also take part. Both tools performed adequately, measured what we aimed to measure and were reliable. Both the Autism Treatment Evaluation Checklist and Pediatric Quality of Life Inventory™ are suitable tools to assess children with developmental and other health problems in Ethiopia and their caregivers. We believe that more similar tools should be developed or adapted for use in low-income countries like Ethiopia, to gain a better understanding of developmental problems in those settings, and allowing clinicians and service providers to use these tools in their practice. Moreover, these tools can be used in future studies to evaluate interventions to improve support for families.