H1N1 is the worldwide emerging infectious disease that spreads through human the same way the seasonal flu viruses spread which is one of the major health problems in the state of Tamil Nadu. This cross-sectional research is studied using R software to analyze the epidemiological features of H1N1 in Vellore district, Tamil Nadu, India in the year 2009. A total of 433 cases of H1N1 were reported during the period August 2009 to July 2010 in and around Tamil Nadu. The data are analyzed under three categories: demographical, seasonal, and social habits of the infected population. Demographical data were collected from National Informatics Centre, Chennai and Department of Health Services, Vellore. Seasonal information from Vellore Agriculture Department and social habits were collected from admitted patients. We have used Spatial Autoregressive model to predict future H1N1 incidence. It is observed that the number of infected individuals increased during monsoon and postmonsoon season whereas it is less during summer and winter. We have found that most of them were in the age group of 0–20 with a common symptom as cough and sore throat. The highest number of cases was reported with individuals having wheezing and it is observed that the infected host takes 3–6 days to recover from the disease. Our study, clearly reported the prevalence of H1N1 outbreak in Vellore district, India. It also helps the authorities to take a quick decision on the prevention strategies. © 2017 Elsevier B.V.