<p> Additive Manufacturing (AM) enables the production of parts with complex structures, such as triply periodic minimal surfaces (TPMS), which have unique properties, for instance, a high strength-to-weight ratio. This study investigates the influence of TPMS lattice parameters, such as cell radius, cell height and thickness ratio between inner and outer side of the lattice, on the mechanical performance of spur gears. A series of 56 gears with unique gyroid lattices has been designed using nTop® and analysed via finite element simulation in Ansys Workbench. Results suggest that with a mass reduction of 50% in the body of the gear, the gear failure will still occur at the tooth, indicating potential for further mass reduction. Moreover, correlations between lattice parameters and stiffness and stress distribution have been identified. Study compares additionally stress distribution within the gear between various designs. Stress state is visualized as a function of a distance from axis of the gear.</p>