Abstract: A process for drying brewer's spent grains, so as to obtain a product with moisture lower than or equal to 15% by weight, biologically stable in time, with high nutritional value, commercially profitable, and environmentally safe, the process comprising two phases: the first one is a mechanical pressing operation for diminishing the initial moisture of brewer's spent grains from at least 75-80% by weight, up to a lower moisture value of 70% by weight; the liquid obtained is carried to an effluent treatment plant; the solid obtained undergoes a second phase; said second phase consists of thermal drying, having two sub-phases: during the first one, the product is transported through a hot air current while during the second one, it is transported by an air current at room temperature; this way, a final product with a moisture content lower of 15% or less by weight is obtained.