To evaluate the visual outcomes, intraoperative and postoperative complications of Cionni ring implantation in eyes with a subluxated lens associated with Marfan Syndrome. This case series included 15 eyes of 12 patients aged 19-56 years with a subluxated lens secondary to Marfan's syndrome operataed at the Departament of Ophtalmology, Toronto Western Hospital between 2003 and 2007. A 2-eyelet Cionni ring and an AcrySof (Alcon) foldable intraocular lens (IOL) were implanted in 13 eyes. Two eyes had trans-scleral IOL fixation in the ciliary sulcus. Best-corrected visual acuity, wavefront evaluation of eye aberration and complication rates were analysed. In all eyes, capsular bag centration was excellent. Preoperative visual acuity ranged from 20/50 to counting fingers, and improved to better than 20/40 in all eyes. The mean follow-up duration was 14+/-9.49 months. The most frequent postoperative complication was posterior capsule opacification, which occurred in 3 eyes (18.7%), 2 of which required a neodymium:YAG posterior capsulotomy. No eye developed retinal detachment. Total eye aberration, tilt and high-order aberrations with a 6-mm pupil diameter decreased significantly after surgery (n = 5): Total eye aberration decreased from a mean of 14.8+/-5.5 preoperatively to 2.1+/-4.3 microns after the operation. Tilt was decreased from 4.1+/-2.5 to 0.12+/-2.1 microns, and high-order aberrations decreased from 4.37+/-3.8 microns, before the operation, to 1.47+/-3.5 after the operation. Cionni ring implantation is an effective procedure to correct partial lens subluxation and has few complications (during 14 months of follow-up) in patients with Marfan's Syndrome.