Background:This study aimed to review Danish register-studies on seafarers’ and fishermen’s health and safety. Methods: Register-based or register-linked studies from 1970 until 2012 were identified and reviewed. Four categories of studies were included: mortality, hospitalization, specific diagnoses and conditions and accidents. Standardized risks estimates were typically calculated by comparison with the total Danish working population. Results: Elevated rates were found in all four categories. For mortality male seafarers had excess rates of accidents, cirrhosis of the liver, cancer, and suicides, and fishermen of accidents and cardiovascular disorders. Female seafarers in male-dominated occupations also had increased mortality rates. Elevated hospitalization rates for male seafarers were particularly prominent for endocrine/nutritional conditions, cervical discopathy, gastrointestinal and cardiovascular diseases, cancers, hearing impairment, and injuries, and for female seafarers cancers, circulatory and genitourinary diseases and injuries. Fishermen had increased hospitalization rates for cardiovascular diseases, bronchitis, emphysema, lung cancer, gonarthrosis, thoracolumbar discopathy, rotator cuff syndrome, carpal tunnel syndrome, injuries and hearing impairment. Specific diagnoses and conditions: There was an elevated risk of tuberculosis, hepatitis B and certain cancers for male seafarers, and of obesity and occupational accidents for both fishermen and seafarers. Conclusions: In spite of safety measures and significant structural changes in the Danish merchant and fishing fleet, the spectrum of health indicators continues to indicate considerable risk factors in the maritime environment and/or the lifestyle of seafarers and fishermen. Future monitoring of fishermen’s and seafarers’ health will remain essential for implementing appropriate preventive measures.