© 2015 The Authors. Influenza and Other Respiratory Viruses Published by John Wiley & Sons Ltd. Introduction: Influenza disease burden and economic impact data are needed to assess the potential value of interventions. Such information is limited from resource-limited settings. We therefore studied the cost of influenza in Peru. Methods: We used data collected during June 2009–December 2010 from laboratory-confirmed influenza cases identified through a household cohort in Peru. We determined the self-reported direct and indirect costs of self-treatment, outpatient care, emergency ward care, and hospitalizations through standardized questionnaires. We recorded costs accrued 15-day from illness onset. Direct costs represented medication, consultation, diagnostic fees, and health-related expenses such as transportation and phone calls. Indirect costs represented lost productivity during days of illness by both cases and caregivers. We estimated the annual economic cost and the impact of a case of influenza on a household. Results: There were 1321 confirmed influenza cases, of which 47% sought health care. Participants with confirmed influenza illness paid a median of $13 [interquartile range (IQR) 5–26] for self-treatment, $19 (IQR 9–34) for ambulatory non-medical attended illness, $29 (IQR 14–51) for ambulatory medical attended illness, and $171 (IQR 113–258) for hospitalizations. Overall, the projected national cost of an influenza illness was $83–$85 millions. Costs per influenza illness represented 14% of the monthly household income of the lowest income quartile (compared to 3% of the highest quartile). Conclusion: Influenza virus infection causes an important economic burden, particularly among the poorest families and those hospitalized. Prevention strategies such as annual influenza vaccination program targeting SAGE population at risk could reduce the overall economic impact of seasonal influenza.