I would do it like this test(TBytes.Create (65, 66, 67)); -- View this message in context: http://free-pascal-general.1045716.n5.nabble.com/How-to-pass-an-array-of-bytes-directly-in-a-TBytes-param-tp5724202p5724215.html Sent from the Free Pascal - General mailing list archive at Nabble.com.