Drug delivery is a broad field which deals with the delivery of pharmaceutical compounds to the desired site with an aim to achieve maximum therapeutic effect and minimum toxicity in treating a diseased condition. To achieve the goal, a carrier system is required for controlled and sustained drug release. Polymers are an all-time favourite matrix used to control the release of drug at the desired rate. Among the polymers, the biopolymers derived from proteins are attracting considerable attention due to their utility in delivering vaccine and chemotherapeutics in clinical application. Additionally, they are biocompatible,biodegradable, and in certain cases, cost-effective. The review addresses the source, structure and characterization of different proteins used as drug delivery carriers. Along with this, the factors contributing to the release of drug from the protein carrier has also been discussed