The multifarious relationships between nitrogen application, energy consumption and GHG emissions are still not well understood in irrigated potato production system. There is a need to ensure that N and energy use are closely considered to provide useful options for adaptation and to build resilience at the farm level. A field experiment was conducted during the winter (November–March) of 2012–2013 and 2013–2014 at the District Seed Farm, Adisaptagram, Hooghly, West Bengal, India (23°26′N latitude and 88°22′E longitude with an altitude of 12 m above mean sea level), under sub-humid subtropical climatic condition of West Bengal, India. The objective of the study was to assess environmental and economic sustainability in potato cultivation as influenced by nitrogen fertilization. This paper examines nitrogen application and energy consumption relationships for irrigated potato production system in eastern India. Results showed that net energy gain was the highest with the supply of 225 kg N/ha for both Kufri Himalini and Kufri Jyoti and 150 kg N/ha for Kufri Shailja. However, maximum values of energy ratio, specific energy and energy intensiveness were recorded with 300 kg N/ha for all three tested cultivars. Total estimated GHG emission per ha increased with the increase in N level from 0 to 300 kg N/ha, regardless of cultivars. Net benefit of potato cultivation was observed to increase with increasing levels of N application up to 300 kg N/ha (for K. Himalini) and up to 225 kg N/ha (for K. Shailja and K. Jyoti). The highest GRF for K. Himalini was observed at 300 kg N/ha, while for K. Shailja and K. Jyoti the maximum GRF was associated with 150 and 250 kg N application per hectare, respectively.