A bicycle dual control device comprising: - a housing cover, a first supporting member attached to the bicycle handlebar with a mounting member; - a first unidirectional control unit, configured to operate a first control mechanism through a first control circuit, comprising a first operating member linked to the first control circuit and operated by a first acting element to be operated with the hand or fingers of the cyclist, and a first coupling assembly which links said first operating member with said first acting element, therefore the first acting element pivots around a fix first pivot axis of said first supporting member roughly orthogonal to the riding plane of the bicycle; - and a second unidirectional control unit, configured to operate a second control mechanism through a second control circuit, comprising a second operating member linked to the second control circuit and operated by a second acting element to be operated with the hand or fingers of the cyclist, and a second coupling assembly which links said second operating member with said second acting element; Characterized in that: - the second control unit is hydraulic and it is integrated inside the first acting element, - and the second operating member comprises a second master cylinder mounted into the body of the first acting element itself and a second master piston reciprocating within said second master cylinder and biased by means of a second return spring, being the second acting element coupled to the second master piston through the second coupling assembly that pushes said second master piston inside said second master cylinder. - a housing cover, a first supporting member attached to the bicycle handlebar with a mounting member; - a first unidirectional control unit, configured to operate a first control mechanism through a first control circuit, comprising a first operating member linked to the first control circuit and operated by a first acting element to be operated with the hand or fingers of the cyclist, and a first coupling assembly which links said first operating member with said first acting element, therefore the first acting element pivots around a fix first pivot axis of said first supporting member roughly orthogonal to the riding plane of the bicycle; - and a second unidirectional control unit, configured to operate a second control mechanism through a second control circuit, comprising a second operating member linked to the second control circuit and operated by a second acting element to be operated with the hand or fingers of the cyclist, and a second coupling assembly which links said second operating member with said second acting element; - the second control unit is hydraulic and it is integrated inside the first acting element, - and the second operating member comprises a second master cylinder mounted into the body of the first acting element itself and a second master piston reciprocating within said second master cylinder and biased by means of a second return spring, being the second acting element coupled to the second master piston through the second coupling assembly that pushes said second master piston inside said second master cylinder.