Buckwheat groats roasted in 3 Polish grain mills were studied for changes in the content of phenolic compds. (rutin as well as coumaric, ferulic, syringic and vanillic acids) during 4-12 months long storage at below 20 degrees C and humidity below 75%. During the storage, the content of phenolic compds. in most cases decreased, and the rate and direction of the observed changes depended on the prodn. conditions. In general, contents of the phenolic compds. in roasted groats decreased during the storage except for syringic acid.