A Y-connector for medical lines, includes a tubular body provided with a first inlet coaxial to the tubular body and containing a valve device formed by an elastic element, and a second inlet arranged obliquely to the tubular body and communicating therewith between the first inlet and the outlet. The tubular body is formed with an inner septum for deviating a flow coming from the second inlet towards the hollow elastic element prior to directing the flow to the outlet.