Yes ! My syntax was bad. Suppose that the key is unique (should be defined) but not the value: ets:insert(E,{123,2}), ets:insert(E,{456,2}), ets:match(E,{'$1',2}), gives me a strange result: ["{",[456]] I was expected a list of keys or a list of {key,value} J-Ph. Constantin ITS3 Genève www.its3.ch