Abstract: The invention is related to a method for amplifying a methylated target nucleic acid in a sample while avoiding amplification of a non-methylated target nucleic acid by inactivating it. This is accomplished by a restriction enzyme digest after bisulfite treatment of the target nucleic acid. The invention is further related to the use of a restriction enzyme to avoid amplification of a non-methylated target nucleic acid while amplifying a methylated target nucleic acid in a sample and kits for performing the methods according to the invention.