The National Association of School Nurses advocates for body mass index (BMI) screening. Little research describes school nurse practice of BMI screening. In this descriptive study, 25 Ohio school nurses participated in three focus groups. An adapted "Healthy People 2010" Determinants of Health Model guided the research questions. School nurses engaged in multiphasic data collection which was contingent on physical environment, workload, and referrals. Lack of system policy was key barrier in terms of data collection, referral, and follow-up. A key facilitating factor was physical education teachers in terms of reinforcing health. School size and privacy were components of school physical environment that influenced screening. Recommendations on securing adequate resources are presented. Implications for policy included a salient need for reduced SN workload. (Contains 2 tables.)