A kit for the treatment in a sterile environment of a biological fluid of a patient comprises: an intake branch (7) designed to be connected to the haematic circuit of a patient; an activation assembly (8) designed to co-operate with a device for generating pulsating pressure for controlling a flow of the biological fluid at least in the intake branch (7); a delivery- branch (9) set downstream of the intake branch (7) and of the activation assembly (8); and a connection outlet element (50) fluidically connected to the delivery branch (9) and designed to be connected to the haematic circuit of the patient, the delivery branch (9) being designed to co-operate with a means of treatment (5) of said biological fluid. In particular, the kit comprises a first non- return valve (13) and a second non¬ return valve (17) set in line, respectively, on the intake branch (7) and on the delivery branch (9), the portion of activation (8) being set between the first and second non¬ return valves (13, 17).