Electronic steam trap monitoring is disclosed. An electronic steam trap monitor is operably coupled to an outlet of a steam trap and is configured to measure at least one process variable of fluid (liquid or gas) flowing through the trap, when the trap is known to be working normally. The steam trap monitor stores the process variable information obtained during the known operating condition for later comparison. The steam trap monitor obtains a later process variable measurement and compares it to the stored measurement to selectively generate a leakage indication. The steam trap monitor preferably uses a local power source and communicates wirelessly.