The authors present a new approach for the fabrication of active microdisk resonators using focused ion beam (FIB) followed by selective wet-chemical etching. This efficient technique enables the placement of the devices at any region of a sample and facilitates prototyping of monolithical integration. Also, it allows the production of very smooth walls required by the resonators. High-quality resonators with an active region based on high-gain InGaAsP/InP quantum wells are demonstrated using this technique. Emission in the C-band at whispering-gallery modes is observed.