Variations in diurnal preferences for activity and sleep have long been classified as morning and evening chronotypes. Although morning and evening-types do not differ in sleep architecture, earlier studies have revealed the association between eveningness and psychopathology. However, most of these works had been conducted only with patient samples. Additionally, previous research has also discovered that morning-types have a healthier lifestyle than evening-types. Therefore, the aim of the present study was to assess the associations between chronotypes and general well-being and psychopathology levels in practically healthy young adults, whose physical and mental health were both examined precisely prior to the research, for the first time in the literature. We found that morning-type individuals have significantly better health conditions than evening-types. And, participants exhibiting a tendency to evening-type were more prone to develop psychological symptoms than subjects exhibiting morning-type chronobiological characteristics. Mental health professionals should be aware that eveningness may be a risk factor for mental and physical health even in currently well young adults. © 2013 Copyright Taylor and Francis Group, LLC.