Understanding the unique needs of school nurses is crucial for developing strategies to increase use of evidence-based health care practices in schools. This article describes the development and evaluation of an instrument designed to identify the needs of school nurses and variables associated with use of evidence-based practice in the school setting, that is, the School Nurse Evidence Based Practice Questionnaire (SN-EBP). After questions were drafted, reviewed, pilot-tested, and revised, data were collected from 386 school nurses for psychometric testing. The initial version consisted of 91 content items in five sections. Principal components analysis with promax rotation identified 17 factors in the five sections of the questionnaire, with Cronbach's alpha coefficients for the sections ranging from .62 to .89. The questionnaire showed good discrimination between known groups on key factors. The SN-EBP was reduced to 69 content items and demonstrated sufficient reliability and validity to warrant further use. It is the only scale available for use in identifying needs and variables associated with use of evidence-based practice in this population.