Reported in French and English is the Congress on the Integration of Science Teaching held at Droujba, Bulgaria in September, 1968. Integration of science is discussed under the headings (1) complete integration and (2) between discipline coordination. The problems of training teachers for integrated science and the special aspects of the integration of science in developing countries are discussed. A series of 15 conclusions are drawn which provide guidelines for an integrated science program. Some 25 countries were represented at the conference. (GR)