The study has revealed that over-exploitation of groundwater has effected drastic changes in energy input-use and energy output produced across the regions in Coimbatore district and the Tamil Nadu state. Energy equivalent values have been used for various direct sources of energy (human, animal and mechanical power), indirect sources (fertilizers, pesticides, manures), commercial, non-commercial, renewable and non-renewable energy sources to analyse the economics of energy usage in the agricultural production process in the two different groundwater development regions of the Coimbatore district. Energy inputs usage has been found very high in groundwater less-exploited area of Perur in paddy and cotton crops. For the coconut crop, Palladam block has shown consumption of more energy-inputs. Energy output-input ratios for paddy, coconut and cotton have been reported as 0.85, 29.35 and 0.09 in Perur region and 0.76, 13.20 and 0.09 in Palladam region. The energy efficiency has been observed higher in coconut crop among crops and in Perur among regions. Not much difference has been observed in gross value of output per MJ of energy input in paddy and cotton crops among groundwater severely-exploited and less exploited regions.