As an essential aspect of health, mental health is often viewed through the lens of mental disorders. Positive mental health, for which there is still no universally accepted definition, generally refers to feeling emotionally and psychologically well, and possibly also socially well. Measuring it, in addition to measuring mental disorders, is essential for understanding and improving the overall health of populations. Research by the Institut de la statistique du Québec sheds light on the concept and measurement of positive mental health.