In this present endeavor, the motivation is to decide the surface roughness and random surface roughness from laser speckle patterns. It may be mentioned that when a monochromatic light is allowed to reflect or transmit from optically rough surface the final intensity pattern at a particular distance is found to the combination of many coherent components originated from the rough surfaces. The Interference of these coherent waves are resulted into laser speckle. Also speckles pattern and their contrasts can be utilized to study the surface roughness. For this purpose the surface is illuminated by plane wave and the image is obtained from the help of lens. A suitable recording medium (air) is utilized for this purpose using Rayleight scattering formula and scattering cross - section.