The United Nations Millennium Development Goals have highlighted the usefulness of the infant mortality rate as a measure of progress in improving neonatal health care services, and more broadly as an indicator of basic health care overall. However, prior research has shown that infant mortality rates can be underestimated dramatically, depending on the live birth criterion, vital registration system, and reporting practices in a particular country. These problems are especially great for perinatal mortality. This study seeks to assess infant mortality undercounting for a global dataset using an approach popularized in economics some three decades ago, when researchers sought to create internationally comparable, purchasing power parity-adjusted per capita income measures. Using a one-sided error, frontier estimation technique, it is possible to recalculate rates based on estimated parameters to obtain a standardized infant mortality rate for all countries, and at the same time to derive a measure of likely undercount for each nation.