Membranes have immense potential to be the technology of today and tomorrow but the fouling problem is a great hurdle in its path to glory. Every membrane process suffers from concentration polarization and fouling. This is one of the main reason among others that membranes are not widely used on industrial scale. The maximum research funding is going into the advancements and development of antifouling methods and membranes. It is obvious that every researcher working on membranes have dealt with this problem. Therefore, this chapter explains about the process of fouling in detail along with the methods used worldwide to deal with it. Also, the factors responsible for fouling in addition to mathematical models are discussed beside the common methods used against fouling. The novel strategies with future requirements and developments to eliminate fouling are also discoursed.