A hosiery item spreading unit with pneumatic feed, usable with pneumatic hosiery item conveyance systems equipped with a centralized suction, comprising: a structure which forms an elongated spreading chamber arranged with its longitudinal axis substantially horizontal and provided, at its longitudinal ends, respectively with a first opening, connected to a duct for feeding the hosiery item to be spread, and with a second opening, connected to a suction duct which can be connected to suction means; the spreading chamber being closed, in a downward region, by a door which can be opened on command to remove the spread hosiery item and containing also elements for gripping a longitudinal end of the hosiery item which are spaced from the first opening towards the second opening. The spreading unit further comprises an auxiliary duct which connects the hosiery item feed duct to the suction duct and valves which can be actuated on command selectively into first, second and third operating positions, for respectively conveying a hosiery item into the spreading chamber, spreading out and eventually allowing removal of the spread hosiery item.