Mental health, an essential aspect of overall 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 socially well as well. Measuring positive mental health—which complements the measurement of mental disorders—is essential to 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.