Thiruvarur lies in the Kaveri River basin and the main occupation of the inhabitants of the town and surrounding regions is agriculture. More than 70% of the workforce is involved in agriculture; 14% being cultivators and rest are agricultural labourers. Paddy is cultivated in three seasons namely Kuruvai (June–August), Samba (August–January) and Thaladi (January–March). The daily wages of the agricultural labourers is more than the rates fixed by the Tamil Nadu government, but due to the decline in number of days of work, the income levels are lower. As of 1998, the male labourers were employed 150 days a year, while the female labourers for 120 days. A government report in 2006 put these numbers at 120 and 100 days respectively. Due to the discontinuity in the working days, the labourers migrate to other states like Gujarat and Kerala. They also shift to other professions like construction industry in the urban centres and textile industry in the district. There are no industrial estates in the town and the district – as of 2012, a government proposal is formulated to develop one at Vaippur village. Modern agricultural tools like hullers have replaced labourers and reduce the profit margin of small trders and labourers. There are no co-operative societies who acquire the farm products and the District Purchasing Centre, operated by the government of Tamil Nadu is the major procurer.
Being an agricultural town, the predominant industries are agriculture based like modern rice milling, palm oil refinery, poultry, live stock and coir based. Tamil Nadu Civil Supplies Corporation operating a modern rice mill and South India Edible Oil involved in refining oil are the large scale industries in the town. There are small service enterprises involved in automobile servicing, hotels, hospitals, boat repairing and nylon fishnet repairing. There is a weekly market at Thanjai Salai and a daily market maintained by the municipality, where vegetables and fish are
