Dockers in the port facilities are exposed to significant psychosocial risks (stress, suffering at work, etc.) related to heavy organisational, environmental, physical, chemical constraints, etc. These workers are particularly affected by the consumption of psychoactive substances because of the dangerousness and complexity of their work. To what extent can these numerous occupational risks be at the origin of behaviour favouring the consumption of psychoactive substances? However, in our country no study has investigated toxic habits in this population. The aim of this study was to determine the prevalence of the use and misuse of psychoactive substances amongst dockers, and to appreciate the poly-consumption according to socio-demographic and occupational characteristics. This cross-sectional study was conducted amongst 665 dockers. The interview took place at the occupational health service and lasted between 15 and 20 minutes for each person respecting the confidentiality. The questionnaire covered socio-demographic characteristics, socio-professional characteristics, and toxic habits (tobacco, alcohol, cannabis and others psychotropic substances). The misuse was assessed by specific tests: Fagerström test for tobacco smoking, Cannabis Abuse Screening Test (CAST) and Alcohol Use Disorders Identification Test (AUDIT). The prevalence of use was 30.5% for tobacco smoking, 9.1% for cannabis smoking, and 16.5% for alcohol consumption. The prevalence of toxic habits was significantly higher in handlers than in machinery operators: tobacco smoking (39.7% vs. 27%; p = 0.002), snuff tobacco (12.5% vs. 4.6%; p = 0.001), hookah (7.6% vs. 2%; p = 0.001), cannabis smoking (20.6% vs. 4.5%; p = 0.001) and alcohol consumption (22.3% vs. 14.3%; p = 0.019). Amongst consumers, the prevalence of dependence or misuse was 45.3% for tobacco smoking, 56.7% for cannabis smoking and 44.5% for alcohol consumption. Fifty-two point five per cent had no toxic habit, 36.7% had one toxic habit, 9.9% two toxic habits, and 0.9% three toxic habits. The most frequent associations were tobacco-alcohol (6.5%), and tobacco-cannabis (3%). Occupational health professionals have to play a key role in raising awareness and fighting against consumption of psychoactive substances amongst dockers.