A study was conducted to analyze the Socio economic impact of eucalyptus cultivation in Pudukkottai district of Tamil Nadu. Eucalyptus globus and Eucalyptus hybrid were the most commonly cultivated species in the district. Survey was conducted among 120 farmers cultivating eucalyptus in their land. The study was conducted in Nilayapatti, Pulvayal and Nachandhupatti villages of Pudukkottai district. The sample size includes 20 commercial cultivators and 100 conventional cultivators. Structured questionnaire was administered collect information to analyze the cost of cultivation and economic analysis of eucalyptus cultivation, people’s knowledge about environmental impacts of eucalyptus etc. Analytical tools like Cost of Cultivation, Net Present Worth (NPW) and Benefit Cost Ratio (BCR), Ordinary Least Square (OLS) and Logit Regression analysis were employed. The study concluded that eucalyptus cultivation was much suitable for marginal and barren lands. Most of the people were aware that eucalyptus cause environmental impact as it was a natural bio drainage crop and cause allelopathy effect on neighboring field plants with the release of secondary compounds but, it does not affect the mindset of the farmers to adopt eucalyptus cultivation in larger extent. Around 70 per cent of the respondents were into eucalyptus cultivation despite knowing the impacts only because of higher income, less maintenance and fast growth of the plant. From the study we obtained profitable cultivation with BCR ranging 4 to 6.