A field experiment was conducted during the dry season of 2007-2008 and 2008-2009 at Rudranagar village in Sagar Island of South 24 Parganas, West Bengal, India to find out the response of Azospirillum inoculation at varying levels of fertilizer nitrogen on growth, yield components, yield and economics of boro rice. The results of the study showed that Azospirillum inoculation progressively increased the growth, yield contributing parameters, grain and straw yield of boro rice with the incremental application of fertilizer N up to 100 kg ha -1. Azospirillum inoculation along with 100 kg N ha -1 registered the higher grain and straw yield, economic returns and benefit-cost ratio to rice and could save at least 30 kg N ha -1 which could be benevolent to the resource poor boro rice growers of coastal Sagar Island in West Bengal.