The technique of modification of the histogram of an image can be applied to the problem of image enhancement. Global histogram equalization and local area histogram equalization are two well-known techniques for the same purpose. In this paper new method is proposed to enhance the contrast of bimodal MRI images using histogram specification with Gamma distribution. The method is aimed to read the original image and calculate its histogram original histogram then apply the Maximum Likelihood Gamma Distribution (MLGD) method to get an accurate statistical information of the original histogram as the means and prior probabilities of the two modes, then we separate the two modes by shift the first mode left or shift the second mode right or perform both shifts. After that we will generate a new histogram called “Desired Histogram” using the new data. By applying a histogram specification method, a high contrast image will be produced. The new method of contrast enhancement of MRI image using histogram specification with Gamma distribution has been tested and showed good results.