We present a hydrogen-powered lawn mower which was adapted from a commercial model running on gasoline. The necessary modifications include adjustments to the carburettor and the installation of a hydrogen reservoir containing about 5 kg of a metal hydride powder. Hydrogen is obtained by desorption of that powder at ambient temperature and 2–20 bar pressure. The reservoir is rechargable at a hydrogen pressure of about 25 bar within less than 1 h. One charge lasts about 40 min. corresponding to about 800 m2 of cut lawn. The engine shows a reduced noise level and no tendency to backfiring. The prototype has run successfully for more than 1 year.