Implementation of system of credits and score-rating of students' knowledge at the medical faculty of Peoples' Friendship University of Russia is considered. Estimation of maximum possible rating for each discipline is conventionally based on mode of "one credit - 36 study hours of student - 36 scores". System of numerical score elaborated at Course of h istory of medicine considers attendance of lectures and studies, activity of student during study hours and self-instruction (term papers included), contribution of student into chair research, interim testing and test passing. Total score of discipline determines rating of student for study class, university year and faculty. Tables of score estimation, its relationship with conventional system of scores are discussed. Examples of evaluation of student's knowledge using score-rating system are presented.