Family and Children of Ukraine, the Ukrainian component of the European Longitudinal Study of Pregnancy and Childhood, is a prospective, geographically-based study to evaluate pregnancy outcomes in 8,000 women in five cities in Ukraine and follow the cohort of births through 7 years of age. Family and Children in Ukraine has been the major collaborative research project for the University of Illinois' Fogarty-funded program, International Training and Research in Environmental and Occupational Health. This Fogarty program includes graduate training, U.S.-based training of visiting scientists, in-country training, and collaborative in-country research. Factors that have contributed to the success of the collaboration include: 1) its focus on the environmental health of mothers and children, which is a priority goal for both countries; 2) the adoption of an internationally-endorsed research protocol with strict quality-control criteria, specifically designed for international collaboration; 3) the establishment of an in-country data management center; and 4) the investment in a long-term research program rather than a short-term study. The major obstacles have been the difficult economic situation in Ukraine, which limits in-country research investment, and the difficulty in obtaining U.S. funding for an international research program.