OBJECTIVE: The aim of this study was to compare the cost-effectiveness of intraocular lens material (PMMA, silicone, acrylic hydrophilic, and hydrophobic) implanted during cataract surgery with reference to Yag-laser capsulotomy and Yag-laser complications in four European countries (France, Italy, Germany and Spain). Setting: A retrospective review of 1525 patients (eyes), aged 50 to 80 years, operated with phaco-emulsification for cataract in 1996 or 1997 in 16 surgical centres (4 per country). METHODS: The study was conducted using a cost-effectiveness approach. Medical charts were reviewed to collect retrospective information during the 3-year period following cataract surgery in order to identify patients who underwent YAG laser capsulotomy post-operatively. Clinical data were combined with unit costs assessed by experts for Yag laser capsulotomy and Yag complications. A cost-effectiveness ratio (cost per patient without Yag laser capsultomy intervention) was estimated in relation to each IOL material used in each of the 4 countries. RESULTS: Ranking the materials in the countries shows that hydrophobic acrylic is number one in all the countries except Germany where it was second. PMMA had the best ratio in Germany, was second in Spain and only third in Italy and France. Silicone was second in France and ranked third in the other countries. Hydrophilic had the worst ratio overall in all countries. CONCLUSIONS: Cost effectiveness ratios of hydrophobic acrylic were better than those of the other types of IOL materials used in most countries. Sensitivity analyses were performed to vary the base case analysis to demonstrate the economic importance of the assumptions. In all cases, acrylic hydrophobic IOL material was shown to be a cost-effective option.