The same conventional varnishes which are produced for untreated wood are used for heat treated wood, which is a popular material in recent years, too. Heat treatment causes changes on chemical properties of wood and consequently on physical and surface properties of wood. Because of this, performance of these traditional varnishes can be different on the heat treated substrate. In this study, effects of surface machining and varnish types on the adhesion of varnishes on the heat treated wood were investigated. Planed and sanded heat treated iroko (Chlorophora excelsa), Scots pine (Pinus sylvestris) and ash (Fraxinus excelsior L.) wood surfaces were coated by using solvent base (HD), acrylic based waterborne (AS), alkyd based silicon-containing (SI) and urethane alkyd based one component polyurethane (PU) varnishes and varnish adhesion values were determined. The highest adhesion was determined in samples coated with polyurethane varnish. The highest adhesion values were 4.98 MPa, 5.88 MPa, 6.61 MPa in untreated, planed and coated with polyurethane varnish scots pine, iroko and ash, respectively.