A scientific workshop was held with specific emphasis on genetic improvement of resistance to mastitis based on SCC. The first objective was to present current knowledge of physiological and genetic aspects of resistance to mastitis. The second objective was to provide a forum for discussion of various strategies for genetic improvement of resistance to mastitis with particular emphasis on use of genetic evaluations for SCC. Contributions covered physiological, immunological, and genetic aspects of resistance to mastitis and SCC, as well as developments in genetic evaluation for SCC.