School nurses are afforded minimal resources related to assessing pain in students with intellectual disability (ID) and have called for continuing education. The purpose of this study was to measure the effectiveness of an education program regarding best practices for assessing pain in students with ID. Educational sessions were presented to 248 school nurses. Pre-, post-, and follow-up surveys measured (1) difficulty school nurses face when assessing pain, (2) knowledge and use of pain assessment methods, and (3) intent to change and actual changes to professional practices. Participants experienced less difficulty assessing pain following the educational program. Almost all participants intended to change pain assessment practices, but large caseloads limited new practice adoption. Policy makers must consider population size and acuity when determining school nurse staffing. Trainings and other resources should be made available to school nurses in order to make pain assessments for students with ID more thorough and efficient.