The cotton ginning, extraction of oil from various oil seeds, cotton and chilly trading are the main business in this district. Many Textile industries are located in and around Theni as the climate is suitable for Textile Industries and it provides employment opportunity for the local people. 

   Vermiculate used for manufacturing cement and paints are available in Cumbum Valley  area.  Once famous  for its agricultural products,  it  retains  its agricultural tint of economy and remains a backward industrial area. Industrial estates have come up with orientation for small  scale and cottage industries. 
This clubbed  with  liberalised  financing  by  nationalised banks  and  new enter prenatal  stimuli,  a dimensional change in the  district's  economy  is visible  in the last decade. Handloom weaving is the major household  industry in the district. Other important items of making toys and dolls, processing of food articles, manufacturing of safety matches and its allied articles  etc. are  worth  to mention. Coarse blankets are made in Periyakulam taluk.  This  is generally used by tribal women of this area. Wax  printing  is  done at Periyakulam.This was prevalent on  a  large  scale during olden time.This art is slowly declining due to mechanical printing.