There is a lot of confusion among common people, who are intended to invest their suplus fund in stock market through mutual fund, whether they should opt for systematic investment plan or lump sum investment, if they have both the provisions. It has been told, while investing in stock market either directly or indirectly, that we should not try to time the market rather we should try our time in the market. An effort has been made to compare the SIP with Lump sum investment. Three popular mutual fund schemes one each from three Asset Management Companies having highest Asset Under Management as on March 2015, have been selected for the purpose.