Collagen is an important biomaterial, finding immense application in the field of wound healing. In this study, effect of UV irradiation on aldehydes crosslinked collagen has been carried out. Aldehydes find predominant application in crosslinking of collagen for various end uses. The physical and optical properties of aldehydes crosslinked collagen affected by UV irradiation have been detailed. Viscosity measurements have shown that aldehydes crosslinked collagen has better stability against UV radiation than native collagen. Circular dichroic studies showed that prolonged exposure to UV radiation changes the triple helical structure of collagen into random coil conformation. The difference spectra for both emission and absorption show that formaldehyde brings about more stability to collagen against UV irradiation than gluteraldehyde. (c) 2007 Wiley Periodicals, Inc.