Abstract. The southern state of Kerala, India was seriously affected by a chikungunya epidemic in 2007. As this outbreak was the first of its kind, the morbidity incurred by the epidemic was a challenge to the state's public health system. A cross sectional survey was conducted in five districts of Kerala that were seriously affected by the epidemic, using a two-stage cluster sampling technique to select households, and the patients were identified using a syndromic case definition. We calculated the direct health expenditure of families and checked whether it exceed the margins of catastrophic health expenditure (CHE). The median (IQR) total out-of-pocket (OOP) health expenditure in the study population was USD7.4 (16.7). The OOP health expenditure did not show any significant association with increasing per-capita monthly income.The major share (47.4%) of the costs was utilized for buying medicines, but costs for transportation (17.2%), consultations (16.6%), and diagnoses (9.9%) also contributed significantly to the total OOP health expenditure. The OOP health expenditure was high in private sector facilities, especially in tertiary care hospitals. For more than 15% of the respondents, the OOP was more than double their average monthly family income.The chikungunya outbreak of 2007 had significantly contributed to the OOP expenditure of the affected community in Kerala.The OOP health expenditure incurred was high, irrespective of the level of income. Governments should attempt to ensure comprehensive financial protection by covering the costs of care, along with loss of productivity