<p>The application of high strength structural steels in different welded structures is growing progressively. Both quenched and tempered as well as thermomechanically treated steel base materials are developing at a faster rate than the filler metals used in their fusion welding processes. Therefore, the selection of filler metals requires and deserves special attention and consideration. Welded structures made of high strength steel are often operated under cyclic loading conditions, which can cause initiation and propagation of fatigue cracks and can lead to catastrophic failure of the structural element or the structure. This characteristic should be considered when selecting filler metals, both during design and fabrication. In order to study this issue, butt welded joints were made from base materials in the 700–1300 MPa strength category, applying gas metal arc welding process. The used filler metals were of the undermatching, matching, or overmatching types, depending on the strength of the base materials. High cycle fatigue tests were performed on specimens machined from base materials and welded joints in different directions; therefore, the crack paths were different too. From these investigations, the parameters of the “Mean – 2SD” S–N curves were determined for each base material and base material–filler metal pairing. The results showed that the matching phenomenon has a significant effect on the crack propagation behavior and the high cycle fatigue resistance of the welded joints; furthermore, the effect depends on the strength category of the base material.</p>