Despite recording double digit growth since 2000, Armenia's tax-to-GDP ratio has been fairly stable at about 141/2 percent. This paper catalogues a range of factors that may account for Armenia's stubbornly for tax collection by benchmarking Armenia's tax-to-GDP against some comparator countries and conducting an extensive econometric study of the main determinants of tax collection. We find empirical support for the hypothesis that the persistence of Armenia's low tax-GDP ratio can be traced to persistence of weak institutions and a large shadow economy. The gap between the potential and actual tax collection in Armenia could be as high as 61/2 percent of GDP. We conclude with some policy recommendations that, if adopted, can boost revenue buoyancy.