Topology optimization applied to additive manufacturing is habitually conceived as a strategy to allow geometries of high complexity, given that additive manufacturing does not impose such severe restrictions in fabricating structures with complex shapes. Nevertheless, additive manufacturing does present certain geometric limitations which are essential to incorporate into the optimization algorithms. The present study describes a topology-optimization methodology oriented to CFF technology (Continuous Fiber Fabrication), in which the isotropic matrix is reinforced with carbon fibers, obtaining components with superior mechanical properties. Despite its advantages, the fiber insertion introduces significant geometric constraints that must be contemplated during the optimization process. The proposed methodology integrates, on the one hand, the consideration of the inherent orthotropy of continuously fiber-reinforced materials and, on the other hand, the imposition of geometric restrictions related to the “minimum length scale”, thus ensuring that the design adapts both to the geometric limitations and to the prescribed reinforcement directions.