Catalytic partial oxidation of methane to synthesis gas was performed over La-M-O, with M = Co, Cr, Ni, Rh. The best system, La-Rh-0, gave 95% conversion with 98% selectivity to carbon monoxide even after 120 h on stream at 800-degrees-C. La-Ni-O deactivated after about 17 h on stream, probably due to coke formation. La-(Ni,Rh)-0 showed improved stability compared to La-Ni-O. La-Co-0 gave mainly carbon dioxide during the first 30 h of the test. Then the activity changed to give mainly carbon monoxide. Some deactivation was observed during the next 50 h test. La-Cr-O produced mainly carbon dioxide. In order to stabilize the small metal clusters formed on the catalyst surface, a second metal will probably have to be included in the perovskite structure.