The demanding environment of the consulting industry seems to be incompatible with the principles of the Quality of Work-Life (QWL), these principles intend to promote the psychological and the physical well-being of the individual's life in general. This study intends to contribute to the study of the effects of the Work-life balance (WLB) on the mental health (psychological distress and psychological well-being) and subsequently on the Quality of work-life. The present research explores the case of an Engineering Consulting Firm located in the province of Quebec. The results obtained are relevant because they demonstrate that the main concerns for the consultants in terms of WLB are the lack of flexibility and the work schedule. These two variables are positively correlated to the psychological distress. The results also coincide with the conclusions obtained in other studies. For instance, in several European countries the lack of flexibility at work is perceived as the main factor that increases the conflict between work and private life.