Lifestyle's alterations are hazardous for health. On one hand they produce a high rate of mortality and disease, on the other hand they cause a reduction of work outcomes and an increase of occupational accidents with important consequences for both worker's health and his/her financial status. The aim of this study is to review the scientific literature for possible relationships between mental health and lifestyle alterations of young workers. We considered as lifestyle factors the attitudes towards: smoking, alcohol consumption, eating, use of medications and doping substances, physical activity and sleeping. From our study it clearly emerges the existence of correlation between lifestyle habits and mental health; in fact behavioural alterations can produce problems of mental health and vice versa. Furthermore, some work peculiarities can lead to psychic disturbances and/or to unhealthy habits which can themselves cause negative effects on working activity. It is very important for young workers to understand that unhealthy behaviours, which can be corrected, are hazardous in terms of health and safety for both the single worker and the collectivity and that those behaviours can enhances the other working risks. Because there is a close interaction between mental health and lifestyles, it would be necessary a careful promotion of mental health on workplaces and to take all the preventive measures, with particular regard for those related to the work organization, in order to reduce the onset, exacerbation and unmasking of mental disorders and psychological difficulties. In working environment, the occupational health physician and his relationship with the patient are of fundamental importance. During preventive and periodic medical examinations, the occupational health physician should take detailed information on young worker's habits regarding smoking, alcohol consumption, eating, physical activity, sleeping, pharmacological abuse and possible presence of mental disorders and furthermore he/she should actively take part in the information and education process of the worker.