This book is designed to facilitate teaching and informal discussion in a supportive and friendly environment. The seminar provides a forum for postgraduate students to present their research results and train their presentation and discussion skills. Furthermore, it allows for extensive discussion of current research being conducted in the wider area of advanced structured materials. Doing so, it builds a wider postgraduate community and offers networking opportunities for early career researchers. In addition to focused lectures, the seminar provides specialized teaching/overview lectures from experienced senior academics. The 2023 Postgraduate Seminar entitled "Advanced Structured Materials: Development - Manufacturing - Characterization - Applications" was held from 20 till 24 May 2024 in Porto. The presented postgraduate lectures had a strong focus on polymer mechanics, composite materials, and additive manufacturing.