During the last 10 years, marine invertebrate pathology has moved from morphological description and microscopic diagnosis of pathogens to molecular characterization of these pathogens and probebased diagnostics. Studies of host-pathogen interactions were undertaken to understand the immunity of molluscs and shrimps with a special new emphasis on immune gene characterization. Recently, genetic transformation has been considered for selecting resistant strains because of the numerous successes obtained with transgenic plants and vertebrates. The production of transgenic molluscs and shrimps, with genes or antisense sequences conferring resistance to specific pathogens, certainly constitutes a new priority for aquaculture. The quick development of research from pathology to immunology and genetics has been made possible partially by developing international cooperation to compensate for the limited manpower, on one hand inside the network of the pathologists, and on the other hand by removing barriers between topics. Regular meetings appear useful for regularly managing research in pathology-immunology-genetics of molluscs and shrimps, for analysing the strategy according to advances in similar fields related to other animal or plant groups, and for improving international cooperation between all scientists concerned from developing and developed countries. © 1995.