High-power cw operation of horizontal-cavity, monolithic InGaAs/GaAs surface-emitting lasers with all dry etched micro-mirrors has been demonstrated for the first time. The 45-degrees and 90-degrees micro-mirrors of the devices were fabricated by ion-beam etching and reactive ion etching techniques, respectively. Threshold-current densities of less than 500 A/cm2, external differential quantum efficiencies of 10% (0.12 W/A) from the emitting facet, and output powers in excess of 100 mW were achieved from uncoated devices driven under cw operation.