A medical stopcock device comprises a housing configured to allow a flow of liquid therethrough, and a cock configured to fit in the housing and switch flow paths of the liquid flowing through the housing. The housing comprises a cylindrical body section formed with a through-hole, an upstream port section provided on an outer periphery of the body section, a downstream port section provided on the outer periphery of the body section and disposed on a side of the body section that is opposite to the upstream port section, and a side tube port section provided between the upstream port section and the downstream port section on the outer periphery of the body section and including a first communication hole, and a second communication hole having an opening area smaller than an opening area of the first communication hole. The cock comprises a cylindrical section configured to be inserted in the through-hole of the body section in a slidable manner, and including a first flow path groove and a second flow path groove, and a handle section configured to rotate the cylindrical section. When the cock is at a reference position, the upstream port section, the side tube port section, and the downstream port section communicate with each other in a manner such that the first flow path groove communicates with the upstream port section and the first communication hole in the side tube port section, and the second flow path groove communicates with the second communication hole in the side tube port section and the downstream port section.
