A professional-type steam iron comprising a known structure composed of a handle (2) fitted above an internally hollow metal plate (3) whose lower surface (3a) is adapted to glide in contact with fabrics; in the lower surface (3a) of the plate and at least in the region (3b) thereof that is considered as being the front region there are respective first and second steam dispensing openings (4, 5) which are internally connected, by means of corresponding first and second ducts (6, 7), to at least one valve means (8) for controlling the supply of steam; the valve means (10) is accommodated in the plate (3) and can be actuated from outside.