A connector for medical lines, comprising a tubular body (1) having a male Luer-Lock accessory (2) at one end, which includes an internal tubular element (3) and an internally threaded external hollow element (4) intended for be threaded with a complementary female accessory, characterized in that it includes an outer jacket (5) coupled in unidirectional rotation with the tubular body (1) in the direction corresponding to the screwing of said male accessory (2) and which can freely rotate in the opposite direction, said outer hollow element (4) of the male fitting (2) is externally provided with an application crown of teeth (7) cooperating with a crown of spring ratchet teeth (6) provided internally with said sleeve (5) ) external for mutual unidirectional rotating coupling in the direction corresponding to the screwing of said male accessory (2), and manually operable torsional coupling means (9, 10) for coupling ar selectively said outer jacket (5) with the tubular body (1) in the direction corresponding to the unscrewing of said male accessory (2)； at least one side push button (8) supported by said outer jacket (5) which is intended to operate said torsion coupling means (9, 10), said at least one side push button (8) provided with a tooth (9 ) of engagement and said tubular body (1) is externally provided with at least one percussion tooth (10), and said lateral push button (8) being radially movable between an inoperative position and an operative position in which said tooth (9 ) coupling interacts with said punching tooth (10).Un conector para líneas médicas, que comprende un cuerpo (1) tubular que tiene un accesorio (2) Luer-Lock macho en un extremo, que incluye un elemento (3) tubular interno y un elemento (4) hueco externo roscado interiormente destinado a ser acoplado a rosca con un accesorio hembra complementario, caracterizado porque incluye una camisa (5) exterior acoplada en rotación unidireccional con el cuerpo (1) tubular en la dirección correspon
