The ethical and societal implications of artificial intelligence systems raise concerns. In this paper we outline a novel process based on applied ethics, namely Z-inspection®, to assess if an AI system is trustworthy. We use the definition of trustworthy AI given by the high-level European Commission's expert group on AI. Z-inspection® is a general inspection process that can be applied to a variety of domains where AI systems are used, such as business, healthcare, public sector, among many others. To the best of our knowledge, Z-inspection® is the first process to assess trustworthy AI in practice.