Purpose: The aim of this study was to evaluate the safety and efficacy of ultrasound cyclo-plasty (UCP) for reducing intraocular pressure (IOP) in patients with glaucoma. Methods: This is a multicentre prospective study conducted in 3 Italian glaucoma centres. UCP was performed by EyeOP1, which delivers ultrasound beams using 6 piezoelectric transducers activated for 4/6 s (first generation) or 8 s (second generation). Primary outcomes were the mean IOP reduction and the rates of success after 1 year. Secondary outcomes were the mean IOP reduction at each follow-up, and the reduction of the number of hypotensive medications. Results: In total, 49 eyes from 47 patients were treated. One year postoperatively, the mean IOP had decreased from 27.7 ± 9.2 to 19.8 ± 6.9 mm Hg (p < 0.001), and the mean number of hypotensive drops and tablets had decreased from 3.2 and 0.5 to 2.3 and 0.2, respectively (p < 0.05). Postoperative IOP reduction was significantly related to preoperative IOP (r2 = 0.5034; p < 0.0001). Second-generation probes determined a significantly higher IOP reduction (p < 0.05). Qualified success was achieved in 25 eyes (51.1%) and complete success in 21 (42.9%), while failure was recorded in 12 (24.5%). Conclusions: UCP is safe and effective for reducing IOP. The procedure determines a greater IOP reduction in patients with higher preoperative IOP. Second-generation probes improve outcomes without detrimental effects on safety.