The invention relates to a machine tool for machining workpieces (P), wherein the machine tool (10) has a first spindle assembly (21) and at least one second spindle assembly (22) each having at least two working spindles (24) which are arranged in a common spindle housing (26, 126) and on which in each case a machining tool (25) for workpiece machining is arrangeable, wherein the machine tool (10) has a workpiece holding device (50) for holding workpieces (P) for the purpose of workpiece machining by way of the machining tools (25), wherein the machine tool (10) has a guide arrangement (30) for the relative positioning of the workpiece holding device (50) holding the workpieces (P) and the first and the at least one second spindle assembly (22) for workpiece machining. In the machine tool (10), provision is made for the first spindle assembly (21) to be guided on a first spindle-assembly guide (31) of the guide arrangement (30) and for the at least one second spindle assembly (22) to be guided on a second spindle-assembly guide (32), separate from the first spindle-assembly guide (31), of the guide arrangement (30), such that the spindle assemblies are movable independently of one another into a working region (A), in which the workpieces (P) are provided for workpiece machining by the workpiece holding device (50), and a tool changing region (W) provided for changing machining tools (25) on the working spindles (24).