With the introduction of minimally invasive techniques, surgeons must learn skills and procedures that are radically dif['erent from traditional open surgery. Traditional methods of surgical training that were adequate when techniques and instrumentatiorl changed relatively slowly may not be as efficient or effective in training substantially new pr'ocedtu'es. Virl, ual environments are a promising medium for training. Because there are few standardized training methods in surgery, there is little information concerning the essential skills that must be trained and assessed. Consequently, exl)eriments and nlodeling are needed to develop an understanding of the basis of surgi(: al skill. Although skilled surgeorls are often said I.o have "good hands," in fact, perfornmnce in surgery is strongly dependent on spatial skills. In this paper, we des(:ril)e a collaborative effort to elucidate the role of spatial skills in minimally invasive surgery using virtual environments, and discuss the potential of virtual environments for assessing and training surgical skills.