Software cost estimation is one of the most challenging task in project management. However, the process of estimation is uncertain in nature as it largely depends upon some attributes that are quite unclear during the early stages of development. In this paper a soft computing technique is explored to overcome the uncertainty and imprecision in estimation. The main objective of this research is to investigate the role of fuzzy logic technique in improving the effort estimation accuracy using COCOMO II by characterizing inputs parameters using Gaussian, trapezoidal and triangular membership functions and comparing their results. NASA (93) dataset is used in the evaluation of the proposed Fuzzy Logic COCOMO II. After analyzing the results it had been found that effort estimation using Gaussian member function yields better results for maximum criterions when compared with the other methods.