A summary of the proceedings of the third world congress on psychiatric genetics is presented. The meeting was held in New Orleans on October 2-5, 1993 and brought together researchers from around the world. The International Society of Psychiatric Genetics sponsored and organized this meeting. Rapid advances of the last few years were reviewed and discussed in terms of their impact on the evolution of experimental design. The importance of definition of heritable clinical phenotypes, and the need to continue to enhance analytic methods were stressed as a priority for the field.