Purpose: The 10/66 dementia research group (DRG) diagnostic tool was devised to diagnose dementia in people with low education in low and middle-income countries. This study aimed to validate the 10/66 DRG tool in Urdu in Pakistan.Methodology: People older than or equal to 60 years were included: (1) With normal cognition: no/low education, high education, and depression; (2) People with mild and moderate dementia. The diagnostic and statistical manual IV-TR clinician diagnosis was used as the gold standard for dementia. The Clinician Dementia Rating scale was used to rate dementia severity. The geriatric mental status AGECAT stage I output was used to diagnose depression. The 10/66 battery was comprised of CSI-D (cognitive screening instrument for dementia), CERAD (consortium to establish a registry of Alzheimer disease), and animal naming test.Result: The sensitivity and specificity of CSI-D COG score for diagnosing dementia was 86.7% and 72.1%, for CSI-D DF score was 71.1% and 96.1%, for CERAD-10 word list delayed recall was 85.9% and 62.2% at a cut point of ≥5 words, and 70.3% and 97.7% for 10/66 diagnostic algorithm.Conclusions: The 10/66 DRG tool is a valid instrument for diagnosing dementia in the Urdu-speaking population, including with low education and depression, in Pakistan. [ABSTRACT FROM AUTHOR]