The present paper reviews the novel area of composite to composite and composite to metal joining, utilizing novel 3D reinforcement technology. The 3D reinforcement pinned technology extends the use of micro-pins from through-the-thickness laminate reinforcement to joints, while introducing AM (Additive Manufacture) and CMT (Cold Metal Transfer) technologies to the joint research field. The great advantages that this novel joining technique provides are lightweight connection, increased strength and significant improvement in damage tolerance. However, the concept has not been extensively explored in all loading nor environmental conditions and on the effects of the various design and manufacturing parameters.