This paper describes datasets from two related surveys conducted in Germany: PIAAC and PIAAC-L. PIAAC is an OECD-initiated assessment that measures the cognitive skills of adults (aged 16–65 years). Around 40 countries worldwide participated in the first cycle of PIAAC. The German PIAAC data were collected in 2011/12. In the longitudinal follow-up survey to PIAAC, PIAAC-L, respondents from the German PIAAC sample were re-interviewed in 2014, 2015 and 2016. Data from both surveys can be used by researchers for a wide range of secondary analyses, for example on correlates of cognitive skills and changes and stability of these skills over the life course.