Abstract: A system and method for odorizing natural gas in a pipeline uses an odorant injection pump operated by a programmable controller. In response to measured gas flow in the gas pipeline, and a preset setpoint, the injection pump injects liquid odorant directly into the pipeline. A flowmeter in the odorant line measures the amount of odorant actually injected to confirm that the required amount enters the pipeline. If the amount of odorant actually injected differs from that which is required by the setpoint, the controller compensates for the difference. The controller preferably logs pertinent data about operation of the system. The controller can be reprogrammed remotely to simplify the task of changing system operation.