A FACTOR ANALYSIS OF 28 INSTITUTIONAL CHARACTERISTICS OF ALL CANADIAN AND AMERICAN MEDICAL COLLEGES (N-100) WAS UNDERTAKEN TO DEVELOP A DESCRIPTIVE PROFILE OF MEDICAL COLLEGE ENVIRONMENTS. THE 28 VARIABLES INCLUDED TYPE CHARACTERISTICS, ADMISSIONS REQUIREMENTS, STUDENT CHARACTERISTICS, AND A MISCELLANEOUS CHARACTERISTICS CATEGORY. PRODUCT MOMENT CORRELATIONS AMONG THE 28 VARIABLES WERE COMPUTED AND THE RESULTING MATRIX FACTORED. FOUR FACTORS--AFFLUENCE, CANADIAN VERSUS U.S. ADMISSIONS PRACTICES, SIZE, AND EMPHASIS ON HOSPITAL TRAINING--WERE DETERMINED. THE FOUR FACTOR SCORES WERE ESTIMATED FOR EACH MEDICAL SCHOOL. EACH FACTOR SELECTED HAD VARIABLES WITH HIGH LOADINGS ON ITSELF AND VARIABLES WITH LOW LOADINGS IN OTHER FACTORS. USING THE DOOLITTLE METHOD, MULTIPLE CORRELATIONS BETWEEN FACTORS AND VARIABLES WERE COMPUTED, AND SCALED SCORES (MEAN-50 AND SD-10) FIGURED FOR EACH SCHOOL. CORRELATIONS BETWEEN MEDICAL SCHOOL CHARACTERISTICS AND THOSE OF PARENT UNIVERSITIES WERE ALSO COMPUTED TO DETERMINE THE DEGREE OF INTERACTION BETWEEN THEM. THE RESULT OF THE STUDY IS A FOUR-FACTOR PROFILE FOR USE IN FUTURE RESEARCH ON MEDICAL EDUCATION. THIS PAPER WAS PRESENTED AT THE AMERICAN EDUCATIONAL RESEARCH ASSOCIATION (NEW YORK, 1967). (JN)