Biopolymers are essential for the implementation of bio- and circular economy. Biopolymers are also fascinating materials because of the versatility of their functionalities combined with availability and biocompatibility. This special issue presents nine papers grouped as preparation and processing, material properties and engineering. Two papers are open for free access: 1) Cellulose modification and shaping – a Review by Kerstin Jedvert and Thomas Heinze and 2) Mechanical properties of natural fibre polymer composites by Agnivesh Kumar Sinha, Harendra K. Narang and Somnath Bhattacharya. Volume 37 (2017): Issue 9 (Nov 2017): Special issue: Biopolymer engineering / Issue editor: Pedro Fardim