A centrifugal spreader (100) for manures, fertilizers and granular materials in general comprises a hopper (1) for containing the granular material, a dispensing container (2), a distribution disc (3) which receives the granular material, and a deflector unit (4) positioned in front of the distribution disc with respect to an exit trajectory of the granular material from the distribution disc. The deflector unit comprises a support frame (51, 52) and a plurality of adjustable deflector fins (40, 40') connected to the support frame. Each of the adjustable deflector fins comprises a first portion (41) rotatably connected to the support frame and a second portion (42) slidably associated with a guide element (60) formed in an operating plate (6). The guide element is shaped in such a way that the second portion is slidable in the guide element along a direction of sliding (S) which is transverse with respect to the direction of translation (X) of the operating plate, so as to create a rotation (a) of the adjustable deflector fins.
