The purpose of this tudy was to measure how well diagnostic related groupings (DRGs) perform as length of stay predictors. This study performed a length of stay analysis on the 44,546 patient discharge abstracts from the Presbyterian Hospital in the City of New York in 1980. This study affirms the appropriateness of DRGs as the foundation of the national hospital reimbursement model, as well as the importance of the use of computer technology in the exploration of this research question and in all areas of inquiry.