This descriptive correlational study assessed school nurses' knowledge of and perceived relevance of the "Standards of Professional School Nursing Practice". Of the 1,162 Ohio school nurses sent questionnaires, 345 returned usable questionnaires (30%). The typical respondent was a 50-year-old Caucasian woman with 24 years of nursing experience, 12 years of school nursing experience, and a caseload of 3 public schools serving 1,500 students. Factors that positively related to the school nurses' knowledge and perceptions of the relevance of the standards were age, advanced degree preparation, school nursing experience, and practicing in a metropolitan area. Factors that negatively related to knowledge and perceived relevance were practicing in a rural area and caseload of special needs students. Standards of practice provide a mechanism for defining and supporting practice roles for nurses. Thus, it is important to increase awareness and use of the standards, especially among school nurses practicing in rural areas. (Contains 3 tables and 1 figure.)