Purpose Twenty-five gauge vitrectomy surgery offers potential advantages over standard 20-gauge vitrectomy surgery, but the short-and long-term post-operative complications, such as cataract formation, are still being evaluated. This study quantifies the outcomes seen following 25-gauge vitrectomies. Methods This is a retrospective, consecutive, non-comparative case series of 25-gauge vitrectomies performed between January 2002 and August 2004. Cases without at least 3 months of follow-up and previous vitrectomies were excluded. Analyses were performed with t-test and Kaplan-Meier curves.Results Seventy-one cases met inclusion criteria. The mean age of the patients was 65 years old (SD 11 years). A variety of surgical indications were included. A statistically significant difference was seen between the mean preoperative visual acuity (20/100) and the mean visual acuity at the 3-month post-operative visit (20/60; Po0.0001). A Kaplan-Meier curve established that for all cases 63.4% of eyes required cataract extraction at 1 year. Total mean follow-up time was 8.675.5 months. Conclusions Statistically significant improvement was seen in mean vision by 3 months following 25-gauge vitrectomy. Cataract formation after 25-gauge vitrectomies remains an important consideration.