We demonstrated high-aspect-ratio microdrilling in borosilicate glass with the fourth harmonic of a nanosecond Nd:YVO_4 laser. This laser illumination yielded drilled holes with diameters of φ8.2 ± 3.1μm and φ6.3 ± 1.0μm at depths from 480 to 2040μm and from 1360 to 2040μm, resulting in aspect ratios of higher than 190 and 100, respectively. The profile of the drilled hole and the influence of the beam profile on the hole profile were investigated.