Motorized control system for controlling the movement of at least one leaf for opening or closing, at least partially, an opening, such as a window, in a wall; said system comprising: - an actuator or motor device adapted to be secured to said wall; and - a rotatable element adapted to be constrained to said leaf and to be rotated about an actuation axis (x-X) by means of said actuator or motor device, in such a way as to move said leaf in order to open and/or close said opening; wherein said system further comprises disengageable transmission means, which comprise a drive portion and a driven portion rotatably cooperating with said actuator or motor device and with said rotatable element, respectively, wherein said drive portion and said driven portion have an interface consisting of respective contact surfaces (24, 26) facing each other and wherein said drive portion and said driven portion can be placed in: - a disengaged condition, wherein they are rotatably independent of each other and movable relative to each other among a plurality of predetermined mutual arrangements, each one of said mutual arrangements corresponding to an associated angular position that can be taken by said leaf with respect to said opening; and - an engaged condition, wherein they rotatably cooperate together and are locked into a mutual arrangement which can be selected among said plurality of predetermined mutual arrangements and which corresponds to the desired angular position of said leaf; wherein said drive portion and said driven portion are rotatable relative to one same rotation axis (X-X); wherein said actuation axis (X-X) coincides with said rotation axis (X-X); wherein the motorized control system further comprises a control member adapted to more said drive portion and said driven portion between said disengaged condition and said engaged condition; characterised in that each contact surface (24, 26) has an alternated succession of seats and/or protrusions arranged peripherally with respect to the rotation axis (X-X) and adapted to be coupled, in each one of said mutual arrangements of said drive portion and said driven portion, to respective matching protrusions and/or seats on the other contact surface (26, 24); in that said control member is a lever rotatably mounted about an oscillation axis (Y-Y) in the proximity of the free end of an output shaft of the actuator or motor device adapted to transfer to rotatable element a rotary motion about actuation axis (X-X) via said transmission means; and - in that said lever has a cam profile designed for mutually pushing said drive portion and said driven portion into said engaged condition, when said lever is rotated in said working position, or into said disengaged condition, when said lever is rotated in said idle position. - an actuator or motor device adapted to be secured to said wall; and - a rotatable element adapted to be constrained to said leaf and to be rotated about an actuation axis (x-X) by means of said actuator or motor device, in such a way as to move said leaf in order to open and/or close said opening; - a disengaged condition, wherein they are rotatably independent of each other and movable relative to each other among a plurality of predetermined mutual arrangements, each one of said mutual arrangements corresponding to an associated angular position that can be taken by said leaf with respect to said opening; and - an engaged condition, wherein they rotatably cooperate together and are locked into a mutual arrangement which can be selected among said plurality of predetermined mutual arrangements and which corresponds to the desired angular position of said leaf; - in that said lever has a cam profile designed for mutually pushing said drive portion and said driven portion into said engaged condition, when said lever is rotated in said working position, or into said disengaged condition, when said lever is rotated in said idle position.