Problems of overeducation and overqualification in developed countries have attracted the attention of policymakers and researchers alike. While these phenomena have been clearly conceptualised, their measurement remains complex and controversial. This paper presents an overview of the phenomena and map overeducation and overqualification across countries. Drawing on a broad set of definitions from the literature, they quantify the intensity of overeducation and overqualification for a set of countries that participated in the first two rounds of the OECD's Program for the International Assessment of Adult Competencies (PIAAC). The results highlight marked differences across countries. However, maps differ according to the focus adopted -- be it overeducation or overqualification -- and are also highly sensitive to the specific definition of occupational mismatch selected. Policymakers clearly need to be cautious when interpreting overeducation/overqualification figures. The analysis also allows to further discuss the strengths and limitations of PIAAC for studying overeducation and overqualification.