The Warwick-Edinburgh Mental Well-being Scale (WEMWBS) is a 14-item questionnaire designed to measure positive mental well-being. It was developed by an expert panel and validated using data from student and population samples. The scale consists of positively worded items covering various aspects of mental health, including positive affect, psychological functioning, and interpersonal relationships. It was validated through content validity, confirmatory factor analysis, internal consistency, criterion validity, and test-retest reliability. The WEMWBS showed good content validity, with high Cronbach's alpha scores (0.89 for students, 0.91 for the population). It demonstrated high correlations with other mental health and well-being scales and lower correlations with overall health scales. The scale did not show ceiling effects in the population sample and had good test-retest reliability (0.83 at one week). It also showed lower social desirability bias compared to other scales. The WEMWBS is a short, psychometrically robust scale that is suitable for monitoring mental well-being at a population level. It is particularly useful for evaluating mental health promotion initiatives due to its focus on positive aspects of mental health. However, further research is needed to establish its sensitivity to change. The scale is recommended for use in population-level mental well-being assessments.The Warwick-Edinburgh Mental Well-being Scale (WEMWBS) is a 14-item questionnaire designed to measure positive mental well-being. It was developed by an expert panel and validated using data from student and population samples. The scale consists of positively worded items covering various aspects of mental health, including positive affect, psychological functioning, and interpersonal relationships. It was validated through content validity, confirmatory factor analysis, internal consistency, criterion validity, and test-retest reliability. The WEMWBS showed good content validity, with high Cronbach's alpha scores (0.89 for students, 0.91 for the population). It demonstrated high correlations with other mental health and well-being scales and lower correlations with overall health scales. The scale did not show ceiling effects in the population sample and had good test-retest reliability (0.83 at one week). It also showed lower social desirability bias compared to other scales. The WEMWBS is a short, psychometrically robust scale that is suitable for monitoring mental well-being at a population level. It is particularly useful for evaluating mental health promotion initiatives due to its focus on positive aspects of mental health. However, further research is needed to establish its sensitivity to change. The scale is recommended for use in population-level mental well-being assessments.