We determined the prevalence of influenza-like illness (ILI) among employees of a suburban Ohio school district. In a survey of 412 of 841 employees (49%), 120 (29%) reported ILI symptoms during the school year, and 92 (77%) reported working while ill. Age ≥50 years and asthma were significantly associated with reporting of ILI symptoms. Encouraging school employees to receive the seasonal influenza vaccine and to stay home when ill should be part of a comprehensive influenza prevention strategy.