BackgroundCOVID-19 vaccines were rolled out in South Africa beginning in February 2021. In this study we retrospectively assessed the cost-effectiveness of the vaccination programme in its first two years of implementation.MethodWe modelled the costs, expressed in 2021 US$, and health outcomes of the COVID-19 vaccination programme compared to a no vaccination programme scenario. The study was conducted from a public payer's perspective over two time-horizons - nine months (February to November 2021) and twenty-four months (February 2021 to January 2023). Health outcomes were estimated from a disease transmission model parameterised with data on COVID-19-related hospitalisations and deaths and were converted to disability adjusted life years (DALYs). Deterministic and probabilistic sensitivity analyses (DSA and PSA) were conducted to assess parameter uncertainty.ResultsIncremental cost-effectiveness ratio (ICER) was estimated at US$1600 per DALY averted during the first study time horizon. The corresponding ICER for the second study period was estimated at US$1300 per DALY averted. When 85% of all excess deaths during these periods were included in the analysis, ICERs in the first and second study periods were estimated at US$1070 and US$660 per DALY averted, respectively. In the PSA, almost 100% of simulations fell below the estimated opportunity cost-based cost-effectiveness threshold for South Africa (US$2300 DALYs averted). COVID-19 vaccination programme cost per dose had the greatest impact on the ICERs.ConclusionOur findings suggest that South Africa's COVID-19 vaccination programme represented good value for money in the first two years of rollout.