PURPOSE: To describe a novel technique to reshape the ectatic cornea by means of crescent keratectomy performed with an excimer laser using a mask. METHODS: A crescent-shaped perforation at the base of the mask allowed the laser ablation to be directed only to the intended region, shielding the remaining cornea. This technique was performed in 3 eyes of 3 patients with keratoconus grade 2 to 3. Arcs of 180° and 360° had been performed depending on the severity of the keratoconus. The edges of the crescent were closed by 10-0 nylon interrupted sutures. RESULTS: At 1 year postoperatively, all cases showed improvement in visual acuity, keratometry, and corneal topography. The treatment also reduced optical aberrations and shortened the anterior chamber depth. CONCLUSIONS: Although the preliminary results are promising, there is a need to standardize a nomogram of this technique for treating keratoconus. [ J Refract Surg. 2017;33(12):854–856.]