This course aims to educate in the principles of occupational health services (OHS) in general, and in the strategies for developing Basic Occupational Health Services (BOHS) for primary health care providers. The course consists of the following 7 modules: 1. Introduction to Basic Occupational Health Services, 2. Stepwise development of the OHS system, 3. The BOHS cycle, 4. Surveillance of the work environment and of the workers’ health, 5. Prevention and education, 6. Diagnosis, therapy, rehabilitation, record keeping and evaluation, and 7. Organization and financing of BOHS. The first two modules can be followed for free; for participation of the full course, a small fee is to be paid. The instruction to send an email message is given on the first webpage of the course. Each module has a pre- and post test. Besides, within the modules, the learning is stimulated by questions and immediate feedback. All courses can be followed and displayed on-line or downloaded and printed in any order (except for the questions and tests, which can be read and are examined only online). An e-tutor button is available for asking questions. The material is appropriate for students and workers, who have basic knowledge in health care and occupational health. Many specific terms used are explained in a glossary. The lessons are available in English only.