Abstract: A gas well monitoring device (10) for installation at a well head (26) for determining bottom hole pressure of a well bore is provided. The monitoring device (10) includes a sensing unit (24) disposed at the well head. The sensing unit (24) includes a pressure transducer (60) and a temperature transducer (42) for measuring pressure and temperature of the gas at the well head. Automatic control circuitry (76, 78, 82) periodically sample the output of the transducers (42, 60). A processor (82) is interconnected to the automatic control circuitry (76, 78) for calculating the value of bottom hole pressure based upon the output of the transducers (42, 60). Storage circuitry (86, 88) is interconnected to the processor (82) for receiving and storing at predetermined time intervals related values of the sampled well head pressure and well head temperature, and the calculated value of bottom hole pressure at the predetermined time intervals.