We used the Health Services Commission data from Manitoba, Canada to identify complications resulting from hysterectomy, cholecystectomy, and prostatectomy which led to hospital readmissions. For each procedure, two specialists independently judged whether the readmissions were for surgery-related complications on the basis of liberally interpreted literature guidelines. Then, each pair of physicians met to resolve differences; only complications agreed upon by physicians were retained in our computer-based analysis. The analysis was done in three steps: algorithms were developed using guidelines from the literature, physician input, and 1974 hospital claims; these were then modified using 1975 data; finally, the algorithms were tested with 1976 data. The computerized algorithms developed were compared with the clinical decisions of physician panels. The results showed high specificity, sensitivity, and predictive value. Given the increasing availability of routinely collected data bases, the possibilities for inexpensively monitoring the outcomes of different providers and institutions are appealing. More extensive validation and application of the methodology to a greater number of procedures are necessary to implement such a program.