PURPOSE: To test three related hypotheses about monographs circulation at academic health sciences libraries: (1) Juran's "Vital Few" Principle, sometimes incorrectly referred to as the "Pareto Principle"; (2) most (> 30%) new monographs will not circulate within four years; and, (3) Trueswell's 20/80 rule concerning intensity of monographs circulation. METHODS: Retrospective circulation study conducted at a major academic health sciences library in November 1997 on monographs acquired during 1993, utilizing an online review file. RESULTS: Unexpectedly, most monographs (84%) had circulated at least once in the four years following acquisition. Combining circulation and in-house data revealed that 90.7% of the monographs acquired in 1993 had been used at least once. Small percentages of these monographs produced disproportionately high circulation levels. CONCLUSION: Monographs circulation rates confirm Juran's Vital Few principle. Most monographs circulated at least once in contrast to results reported by the Pittsburgh Study or other studies reported by Hardesty and Fenske. The results do not comply with Trueswell's 20/80 ratio rule. Further research needs to investigate the effects of low students to books ratios and problem-based learning (PBL) curricula upon monographs utilization.