This cross-sectional study was designed to establish diagnostic accuracy of the Patient Health Questionnaire 2 in Qatar’s primary care population. The data required for the study were anonymously extracted from Qatar’s primary care electronic medical record system. The sensitivity, specificity, predictive values, negative values and optimal cut-off points were calculated for the tool. A total of 6921 individuals met the study’s inclusion criteria. The diagnostic accuracy of cut-off values was calculated for scores 1–6. Based on the Youden’s index (0.58), a score of 2 was identified as the most optimal cut-off. It offers a sensitivity of 88.73% and specificity of 69.31%. Further studies should aim to confirm the results using alternative study designs and to report them in accordance to population characteristics both in Qatar and internationally.