This study examines a linkage between the international mathematics scale of the Programme for International Student Assessment (PISA 2012) and the mathematics assessment taken from the German National Assessment 2012 (NA 2012). Previous comparisons of the studies’ theoretical frameworks confirmed a high conceptual similarity. Although both frameworks differentiate on the one hand in four (PISA 2012) and on the other hand in five (NA 2012) content areas, a systematic comparison shows a high conceptual overlap between both studies. There is also a high correlation between both mathematics tests (r = 0.82). This study aims to check further how far both reporting scales could be linked to each other and to what extent the proficiency levels in PISA and in the NA are comparable. The results show that the score distributions of both studies are approximated normally distributed. The results of an Equipercentil-Equating lead to a distribution of PISA-equivalence scores that is close to the distribution of the original PISA-scores. For the total population there is neither difference between both distributions in the mean values, standard deviation, skewness and kurtosis nor in the distributions on the PISA Proficiency Levels. There was evidence for a high quality of scale linking. As expected it could be shown, that the cut score for mathematics competency, at which the learners are counted among the PISA risk group, is lower than for national education standards of mathematics (middle school track) and higher than for the national education standards of mathematics for the lower school track. The article closes with a discussion about the results and the studies limitations.