Collagen is the most abundant protein in vertebrates. Most characteristic feature of this protein is its ability to form supramolecular aggregates in extracellular space. Collagen is widely used for biomedical and pharmaceutical applications owing to its cell attachment capabilities, excellent biocompatibility, biodegradability and weak antigenicity. Application of collagen is a consequence of the ability of collagen to self-assemble in vitro into various strong structures. However, applicability is limited due to its high cost and probability of disease transmission from the current sources. Fish processing wastes could be promising cost effective collagen sources through recycling of those wastes. In the present study, collagen was isolated from scales of Labeo rohita (Rohu) and Catla catla (Catla) through demineralization followed by extraction using dilute acetic acid. The isolated protein was characterized by different physico-chemical techniques like FTIR, SDS-PAGE and CD spectroscopy. Thermal behavior of isolated collagen was evaluated by thermogravimetric analysis. The promising feature of obtained collagen is its close denaturation temperature to mammalian collagen, which significantly boosts its applicability. The isolated collagen may well find application in biomedical and pharmaceutical fields as a potential material for construction of tissue engineering scaffold, wound dressing system and drug delivery device. © 2010 IEEE.