Background: Pain is perceived through different pathways involving thinly myelinated Aδ-fibers and unmyelinated C-fibers. Aδ-fibers are responsible for a quick, sharp pain, whereas C-fibers relate to a lateonset, burning sensation. Several studies suggest that it is essential to investigate nociceptive fibers separately and in relation to each other. The aim of this study was to selectively stimulate Aδ-and C-fibers using a 980-nm diode laser by varying the laser settings and the stimulated surface area in healthy subjects.