Abstract: A portable hat box for a brimmed hat having an upper member and a lower member. The upper member being pivotal relative to the lower member about a pivot axis between a closed position and an open position. The members in the closed position completely enclose a hat chamber. Each of the members having a platen surface. The lower member platen surface is substantially complementary in shape to the upper member platen surface. The platen surfaces are adjacent having a substantially constant vertical clearance therebetween in the closed position. The platen surfaces are nonadjacent and obliquely related in the open position.