This study analyzed the impact of school nurses on economic efficiency. Public schools must provide resources such as books, teachers, and buses necessary to accommodate all enrolled students even if all students do not come to school every day and even if some leave school before the end of the school day. To the extent that resources are allocated but unused, there will be an increase in what is termed "X-inefficiency". To investigate this phenomenon, data related to student absences and student checkouts were collected from 22 schools with a total student population just over 10,000 students during a 20-day period in the fall of 2001. This study found that fewer children checked out of school for medical reasons when a full-time school nurse was available at the school. Additionally, this study supports the contention that full-time school nurses might have a positive impact on the percentage of children with health care insurance coverage. However, a large number of students did check out for what appeared to be less than valid reasons. Thus, although the presence of a school nurse reduced the X-inefficiency, school policy and procedures allowed a degree of X-inefficiency to remain. (Contains 4 tables.)