The main purpose of this paper is to study the opportunities of structural composite material optimization using additive manufacturing, in specific the optimization of varying orientation of continuous fiber direction in composite structures. Recent advances in additive manufacturing, with the introduction of fused deposition modeling of continuous fiber-reinforced thermoplastics, have opened a door for further improvements in composite manufacturing. Optimal orientation of fibers can improve structural stiffness, strength, ultimate failure load, buckling stress, and fundamental frequency of composite laminates. A new technique for composite manufacturing, combining additive manufacturing with advanced composites using a multi-axis robotic arm, opens the door for new optimization methods where composite structures are not only optimize in the in-plane direction but also in the vertical axis. This is believed to yield parts that are stronger, safer, and lighter.