Abstract: The present invention provides a four-port, four-way stopcock having two components, a body and a core, that are assembled together and form a fluid-tight and air-tight seal. The body has a number of connectable ports attached to a central chamber. The core has an axial port and is positioned within the central chamber so that it can be rotated with respect to the body. The core also has two independent fluid passages that can carry fluid between two different sets of ports, simultaneously. For example, the core can be rotated to a position wherein fluid flows between the axial port of the core and one of the connectable ports of the body, while separate and different fluid also flows between two other connectable ports of the body.