The nutritional value of milk is largely undisputed. Colostrum, the first milk produced by mammals after parturition, has been thoroughly studied on recent years, after confirming its superior nutritional and protective value when compared to milk. initially, colostrum was used clinically as a vehicle for passive immunity transfer. It is now known colostrum contains cytokines and other protein compounds of wry low molecular weight that can act as Biological Response Modifiers (BMRs), which intervene locally in most biological processes. This article reviews the composition and current clinical use of colostrum, and describes the use of a colostral derivative in the treatment of rheumatoid arthritis and osteoarthritis.