Abstract: A portable drilling rig for mounting on a flatbed truck or other carrier vehicle, includes a turntable rotatably mounted on the truck bed; a slide pivotally mounted on the top of the turntable for rotation around a horizontal axis; a hydraulic cylinder interconnecting the turntable and slide for raising and lowering one end of the slide so that the slide can be tilted from a transport position to an operating position beside the truck; a carriage slidably mounted on the slide, the position of the carrier on the slide being controlled by a winch, pulley and cable system; a derrick pivotally mounted on the carriage for rotation between the transport and operating positions, and a hydraulic cylinder interconnecting the carriage and the derrick for causing the derrick to move between the transport and operating positions.