Various aspects of current problems in the field of public health will be commented on in an introductory paper. Attention will mainly be paid to three subjects, viz. zoonoses, food hygiene and environmental pollution. Recent developments in the field of so-called classical and currently emerging zoonoses will be briefly discussed with reference to the specific papers which will be presented by specialists during the course of the day. In the field of food hygiene, problems of bacterial and chemical contamination of foods of animal origin will be referred to. Modern aspects related to drastically altered methods of production, distribution and eating habits will be stressed again. Future chief items for further methods studies in this field will be puut forward. In addition to general aspects of problems relating to the environment and pollution, attention will be drawn to the specific contribution of the veterinarian both in the prevention of further pollution and in the possible solution of the highly complicated problems in this field. Real and hypothetical cycles of micro-organisms and chemical constituents in the environment as well as studies designed to disrupt these cycles will be discussed. In considering these problems, reference will be made to more detailed discussions whhich will take place during the course of the day, to the duties of and possibilities for the veterinarian in all these fields of research, to international co-operation and to the research programmes and legal regulations in the Netherlands.