A medical stopcock comprising: a housing in/from which liquid flows; and a cock which is fitted in the housing and switches flow paths of the liquid flowing through the housing, wherein the housing includes: a cylindrical body section formed with a through-hole; an upstream port section provided on an outer periphery of the body section; a downstreamport sectionprovidedon the outerperiphery of the body section and arranged on a side opposite to the upstream port section across the body section; and a port section for a side tube provided between the upstream port section and the downstream port section on the outer periphery of the body section and formed with a first communication hole and a second communication hole having an opening area smaller than that of the first communication hole, the cock includes: a cylindrical section which is inserted in the through-hole of the body section in a slidable manner, and which is formed with a first flow path groove and a second flow path groove through which the liquid passes; and a handle section for rotating the cylindrical section, and in a state where the cock is at a reference position making the upstream port section, the port section for a side tube, and the downstream port section communicate with each other, the first flowpath groove communicates with the upstream port section and the first communication hole in the port section for a side tube, and the second flow path groove communicates with the second communication hole in the port section for a side tube and the downstream port section. a housing in/from which liquid flows; and a cock which is fitted in the housing and switches flow paths of the liquid flowing through the housing, wherein the housing includes: a cylindrical body section formed with a through-hole; an upstream port section provided on an outer periphery of the body section; a downstreamport sectionprovidedon the outerperiphery of the body section and arranged on a side opposite to the upstream port section across the body section; and a port section for a side tube provided between the upstream port section and the downstream port section on the outer periphery of the body section and formed with a first communication hole and a second communication hole having an opening area smaller than that of the first communication hole, a cylindrical body section formed with a through-hole; an upstream port section provided on an outer periphery of the body section; a downstreamport sectionprovidedon the outerperiphery of the body section and arranged on a side opposite to the upstream port section across the body section; and a port section for a side tube provided between the upstream port section and the downstream port section on the outer periphery of the body section and formed with a first communication hole and a second communication hole having an opening area smaller than that of the first communication hole, the cock includes: a cylindrical section which is inserted in the through-hole of the body section in a slidable manner, and which is formed with a first flow path groove and a second flow path groove through which the liquid passes; and a handle section for rotating the cylindrical section, and a cylindrical section which is inserted in the through-hole of the body section in a slidable manner, and which is formed with a first flow path groove and a second flow path groove through which the liquid passes; and a handle section for rotating the cylindrical section, and in a state where the cock is at a reference position making the upstream port section, the port section for a side tube, and the downstream port section communicate with each other, the first flowpath groove communicates with the upstream port section and the first communication hole in the port section for a side tube, and the second flow path groove communicates with the second communication hole in the port section for a side tube and the downstream port section.