Traditional manufacturing techniques for hydrogen pressure vessels have inherent constraints in the possible geometrical and structural optimisation. Using 5-axis Additive Manufacturing (AM) allows for a far greater shaping freedom. This thesis will provide a new manufacturing method for pressure vessels with 5-axis AM. Using the highly anisotropic Liquid Crystal Polymers (LCP) provides both the required hydrogen permeability performance, for storing gaseous hydrogen, as well as opening up a large potential for structural optimisation. LCPs in their additively manufactured form are tested for hydrogen permeability, in order to asses the effect of AM on the bulk permeability properties of this material. Furthermore the 5-axis AM process is developed for LCP pressure vessels, culminating in a series of pressure tests on additively manufactured specimens. These specimens provide a proof of concept for the manufacturing method, which is a starting point for expanding the geometrical and structural optimisation of pressure vessels designs.