In this study, we estimated the benefits of rotavirus vaccination for infants had the rotavirus vaccine been introduced in the Netherlands as of its market authorization in 2006. An age-structured, deterministic cohort model was developed to simulate different birth cohorts over a period of 15 years from 2006 until 2021, comparing both universal and targeted high-risk group vaccination to no vaccination. Different scenarios for the duration of protection (5 or 7 years) and herd immunity (only for universal vaccination) were analyzed. All birth cohorts together included 2.6 million infants, of which 7.9% were high-risk individuals, and an additional 13.2 million children between 1-15 years born prior to the first cohort in 2006. The costs and health outcomes associated with rotavirus vaccination were calculated per model scenario and discounted at 4% and 1.5%, respectively. Our analysis reveals that, had rotavirus vaccination been implemented in 2006, it would have prevented 356,800 (51% decrease) and 32,200 (5% decrease) cases of rotavirus gastroenteritis after universal and targeted vaccination, respectively. Over the last 15 years, this would have led to significant avoided costs and quality-adjusted life year losses for either vaccination strategy with the most favorable outcomes for universal vaccination. Clearly, an opportunity has been lost.