One of the articles contained within European Council Directive 86/609/EEC states that "Persons who carry out experiments or take part in them, and persons who take care of animals used for experiments, including duties of a supervisory nature, shall have appropriate training". In effect, this article stipulates that only competent individuals are allowed to work with laboratory animals. At least three groups of individuals can be identified with different responsibilities toward experimental animals: animal technicians, scientists, and veterinarians/animal welfare officers. The responsibilities and duties of the individuals within each of these categories differ. This paper focuses on the training of scientists. The scientist designs, and often also performs, animal experiments. Therefore, scientists must be educated to develop an attitude of respect toward laboratory animals, and must be trained so that, if an experiment must be performed with animals, it is designed according to the highest possible scientific and ethical standards. In The Netherlands, the law stipulates that scientists intending to work with animals must have completed a course in laboratory animal science. This compulsory course started in 1986. The Department of Laboratory Animal Science at Utrecht University is responsible for the national coordination of this course. Participants must have an academic degree (at the level of MSc) in one of the biomedical sciences, such as biology, medicine or veterinary medicine. Although the course is an intensive 3-week, 120-hour long course, which covers both technical and ethical aspects of laboratory animal experimentation, it cannot provide full competence. It is designed to provide sufficient basic training and knowledge to enable students to design animal experiments, and to develop an attitude that will be conducive to the implementation of the Three Rs. However, full competence will always require further training that can only be acquired as a result of practical experience gained while working in the field of laboratory animal research. Evaluations subsequent to the course have revealed that more than 98% of the students regard the course as indispensable for all scientists working in a research area where animal experiments are performed. They agree that the course not only contributes to the quality of experiments and to the welfare of animals, but also to a decrease in the number of animals used in experiments.