Speckle noise is a granular disturbance, which is an inherent property in echocardiographic images. This usually degrades the image resolution and contrast. The image with speckle noise is very difficult to interpret. Despeckling is necessary to improve the visual quality for better diagnoses. In last thirty years, different methods have been proposed for despeckling of echocardiographic images. In this paper a review of these techniques is done highlighting the different types of filters and evolving approaches over last three decades. The types of filters are mainly divided into linear filers, diffusion filters and wavelet domain filters. The main aim of this paper is to do comparative study of different thresholding techniques in wavelet domain. © 2018, Scientific Publishers of India. All rights reserved.