The cost-effectiveness of introducing infant rotavirus vaccination in Armenia in 2012 using Rotarix(R) was evaluated using a multiple birth cohort model. The model considered the cost and health implications of hospitalisations, primary health care consultations and episodes not leading to medical care in children under five years old. Rotavirus vaccination is expected to cost the Ministry of Health $220,000 in 2012, rising to $830,000 in 2016 following termination of GAVI co-financing, then declining to $260,000 in 2025 due to vaccine price maturity. It may reduce health care costs by $34,000 in the first year, rising to $180,000 by 2019. By 2025, vaccination may be close to cost saving to the Ministry of Health if the vaccine purchase price declines as expected. Once coverage has reached high levels, vaccination may prevent 25,000 cases, 3000 primary care consultations, 1000 hospitalisations and 8 deaths per birth cohort vaccinated. The cost per disability-adjusted life year (DALY) saved is estimated to be about $650 from the perspective of the Ministry of Health, $850 including costs accrued to both the Ministry and to GAVI, $820 from a societal perspective excluding indirect costs and $44 from a societal perspective including indirect costs. Since the gross domestic product per capita of Armenia in 2008 was $3800, rotavirus vaccination is likely to be regarded as “very cost-effective” from a WHO standpoint. Vaccination may still be “very cost-effective” if less favourable assumptions are used regarding vaccine price and disease incidence, as long as DALYs are not age-weighted.