The main aim of this paper is to measure the underground economy of India and to review previous attempts to do the same. In this paper I provide estimates of the size of the hidden economy of India for the period 1971 - 2004. Analysis on previous attempts is done with a focus on the dynamic multiple indicators multiple causes (DYMIMC) and the currency demand methods. I estimate the size of the Indian economy using indicator and causal variables chosen by Schneider, Chaudhuri and Chatterjee in their paper, “The Size and Development of the Indian Shadow Economy and a Comparison with other 18 Asian Countries: An Empirical Investigation”.