This study was conducted to determine the nutritive values of shelled, unshelled oak nuts and their shells. For the estimation of dry matter (DM), organic matter (OM) and crude protein (CP), degradability characteristics, digestibilities, energy values and tannin contents of these feedstuffs the nylon bag technique, cellulose feed system and enzyme methods were used. In spite of the fact that in situ dry matter, organic matter and crude protein degradabilities of shelled and unshelled oak nuts were high, the degradabilities of shells were found lower. Degradability characteristics (a, b, a + b) and effective degradabilities were high in unshelled and shelled oak nuts and low in shells. The differences between the oak nut shells and the other two groups were significant for DM and OM degradabilities (P < 0.01). Pepsin digestible N contents were lower in shelled and unshelled oak nuts and high in shells. Unshelled and shelled oak nuts were significantly different from the oak nut shells for digestibility of DM and OM. Energy values were highest in unshelled oak nuts and lowest in shells. Oak nuts can be used as a forage source in regions with their high natural production.