Abstract. The assessment of the maturity of Privacy-Enhancing Technologies (PETs) is a complex and challenging task, which can only be performed by experts in the eld. However, at the same time, the need for precise technology readiness and quality denitions for PETs emerges rapidly. In order to overcome this gap, standardised means to assess, discuss, and compare PET maturity levels are necessary. In this paper, we propose an approach for assessing the maturity of PETs. We dene both the scales and the methodology for measuring maturity of PETs, in a way that is independent from the domain of application. Based on an in-depth analysis of the criteria to be met by such a PET maturity level scheme, we propose a combined quality-and-readiness level scale to be used for this purpose.