The European Radiation Research Programme refocused some of its research effort within EU countries to consider the environmental consequences of the Chernobyl accident within the third framework period from 1985 to 1989. A gradual improvement in contacts with the Soviet Union occurred from 1990 and allowed the development of research collaboration between EC and Soviet scientists. In response, a programme of Experimental Collaborative Projects (ECP) and Joint Study Projects (JSP) were launched by the EC-DGXII's Radiation Protection Research Action. Within these projects. Western European and Eastern European scientists collaborated on assessing the consequences of the accident, considering remedial actions and acquiring much basic scientific information on the behaviour of radionuclides in the contaminated territories in Ukraine, Belarus, and the Russian Federation. The major goal of all these studies was to provide practical and theoretical assistance to the relevant authorities, based on a fundamental approach of understanding the environmental factors which control the different exposure rates to both the urban and rural populations living in the contaminated areas. The scientific results of the radioecological projects have been summarised at the First International Conference on the Radiological consequences of the Chernobyl accident. This Conference was organised by the European Commission and the Belarus, Russian and Ukrainian Ministries on Chernobyl affairs, Emergency Situations and Health. This paper summarises the achievements of the radioecological programme.