In this paper, a technique for enhancing the low resolution multi spectral image using Discrete Wavelet Transform (DWT) is proposed with the help of the corresponding high resolution panchromatic image. Image fusion, also called pansharpening, is a technique used to integrate the geometric detail of a high-resolution panchromatic (PAN) image and the color information of a low-resolution Multi spectral (MS) image to produce a high-resolution MS image. Remote Sensing systems, particularly those deployed on satellites, provide a redundant and consistent view of the Earth. In order to meet the requirements of different remote sensing applications, the systems offer a wide range of spectral, spatial radiometric and temporal resolutions. In general, sensors characterized with high spectral resolution, do not have an optimal spatial resolution, which may be inadequate to specific task identification in spite of its good spectral resolution. In panchromatic image with high spatial resolution, detailed geometric features can be easily recognized, while the multispectral images contain richer spectral information.