A connector (1) for medical infusion lines, transfusion lines, and the like, comprising a tubular body (2) having at one end a male connector (8) including an inner tubular element (9) and an outer hollow element (10), which is internally threaded and can be coupled by screwing to a complementary female connector. The line connector (1) further includes an outer manoeuvring sleeve (22) coupled in unidirectional rotation to the body (2) in the direction corresponding to screwing of the male connector (8) with respect to the complementary female connector and free to turn in the opposite direction, formed by two parts (23, 24) coupled together on the body (2) of the connector (1).
