Objective: Evaluate the effect of pediatric and household upper respiratory illness/common cold (URI) on employee function. Methods: The CHIEF Study is a prospective cohort study of 2295 United States employees with children among three large Fortune 500 companies. Prospective monthly survey responses are collected during the 2007-2008 influenza season and linked to an administrative health care claims database. The survey component asks employees about the effect of both personal and household member (HHM) illnesses/injuries and URI on their absenteeism and presenteeism. The administrative claims database component includes information about health care utilization and expenditures. Results: Initial monthly results indicate that employees with URI (n=680) reported more days of absenteeism (0.53 vs. 0.44, respectively; p=0.2453) and more hours of presenteeism (0.88 hours vs. 0.38 hours, respectively; p<0.0001) than employees without URI (n=1536). Employees with at least one HHM experiencing URI reported missing more days of work (0.17 vs. 0.06, respectively; p=0.0016) and more hours of presenteeism (0.43 and 0.14, respectively; p<0.0001) than employees reporting otherwise. Among employees reporting URI, symptoms lasted 4.77 days on average—about half of which were “most severe” (2.31 days). Employees also reported that it took 6.20 days to “get back to normal” following symptom onset. Employees reporting URI and any productivity loss missed 1.36 days of work and experienced 2.79 hours of presenteeism because of their symptoms. Productivity was also negatively affected for employees with at least one HHM experiencing URI—employees reported missing 1.25 days of work and having 0.56 hours of presenteeism as a result of HHM symptoms. Conclusion: Employees are significantly less productive—in terms of both absenteeism and presenteeism—when they have URI symptoms. Furthermore, employee productivity is also significantly impacted when a HHM reports URI symptoms.