Efficiency Measures in the Agricultural Sector opens with detailed descriptions of measurement techniques such as Data Envelopment Analysis (DEA) and Stochastic Frontier Analysis (SFA), which are often used to support models in analysis of agricultural productivity, based on mathematical programming (non-parametric, non-stochastic) models or econometric (stochastic, parametric) models. Among the factors studied using these techniques are the abundance of subsidies, strong competition between regions worldwide and the need for efficient production systems. In some countries like Portugal, this sector is being revitalized in face of the need for reducing imports. The editors draw on a 3-year project that analyzed a Portuguese area in detail, comparing this study with papers from other regions. Applications include the estimation of technical efficiency in agricultural grazing systems (dairy, beef and mixed) and specifically for dairy farms. The conclusions indicate that it is now necessary to help small dairy farms in order to make them more efficient. These results can be compared with the technical efficiency of a sample of Spanish dairy processing firms presented by Magdalena Kapelko and co-authors.