Coconut meal (CM) is an industrial byproduct of coconut oil and coconut milk production which may be modified for use as fodder. Here we study the effects of the physical modification of CM. Four modification methods were tested: water soaking, microwave-, γ-, and electron-beam irradiation. We determined the CM chemical composition, physicochemical properties, and in vitro carbohydrate digestibility by digestive enzyme extracts from Nile tilapia (Oreochromis niloticus) and silver barb (Barbonymus gonionotus). CM modifications decreased the level of crude fibre but increased the available carbohydrates (p < 0.05). Furthermore, water soaking changed the physicochemical properties including pH, water solubility, microstructure, thermal properties, and crystallinity. Water soaking also increased the carbohydrate digestibility by the fish enzymes tested. The findings of this study therefore suggest that the quality of CM as a feedstuff can be improved by water soaking.