A critical success factor for Privacy-Enhancing Technologies (PETs), and for Privacy-Enhancing Identity Management in particular, will be user-friendly and intelligible user interfaces that are legally compliant and convey trust. Such user interfaces have to meet challenges such as the user-friendly representation of complex PET concepts (such as “pseudonyms”, “unlinkabilty” or “anonymous credentials”) that are unfamiliar to many users, the provision of security, the enforcement of legal privacy principles, such as informed consent or transparency, as well as the mediation of reliable trust to the end users. In this paper, we will discuss such challenges for usable privacy-enhancing identity management and will provide some HCI guidelines for addressing those challenges.