A tubing drain for service with oil wells, water wells, gas wells and/or thermal wells has a configuration of structural features which allow the drain to be opened and closed without the need to pull the drain to the surface to be serviced. The drain utilizes an inner mandrel having two circumferentially aligned cylindrical apertures which may be selectively aligned with a drain port in an outer shell member as the inner mandrel is rotated within the shell. A first cylindrical aperture contains a ball which, when in alignment with the drain port, is urged against a seat in the drain port by hydraulic pressure. However, when the inner mandrel is rotated the ball is dislodged from the seat and forced back into the first cylindrical aperture. Further rotation of the inner mandrel aligns the second cylindrical aperture with the drain port, allowing the tubing to drain.