The in vivo tissue ablation characteristics of a pulsed holmium: YAG laser (λ = 1,980 nm) were studied. The laser energy was coupled onto nylon fibers 400 and 600 µm in core diameter. Laser incisions were made on white rats at different sites of the tongue and of the mucous membranes of the oral cavity. Power settings of 500 and 1,000 mJ/2.5-ms pulse at 5 pulses/s were used and the tissue responses examined by light microscopy. Wound healing was studied over a 6-week period. The results of this study are promising for future application of the holmium: YAG laser in otorhinolaryngolog