Studies have been made of age- and sex-adjusted 1968 provincial rates for individual surgical procedures. For elective and discretionary operations, such as tonsillectomy and adenoidectomy, hysterectomy, vein stripping and lens extraction, provincial rates varied by approximately 100 percent. Newfoundland, with few surgeons and hospital beds, had the lowest discretionary rates, and Alberta, which ranked hgih both for surgeons and hospital beds, the highest. Interprovincial differences were of smaller magnitude for non-discretionary surgery (radical mastectomy, cesarean section, colectomy., lobectomy, etc.). Ther were statistically significant correlations between numbers of surgeons and elective and discretionary surgical rates and between numbers of hospital beds and bed use in the provinces. The effect of disease prevalence on discretionary surgical rates was minimized because the rates were age- and sex-adjusted. Provincial organization of, and payment for, medical services has been similar. Hence, the ratio of surgical personnel to population in each province is postulated as a major determinant of the differing interprovincial rates.