3D printed custom-made or customisable implants and cutting guides are currently most frequently applied in knee, maxillofacial, and cranial surgery. Evidence of very low or low quality shows significant differences in precision, both in terms of malalignment and deviation between 3D printed technology and standard instrumentation in knee arthroplasty. Evidence of higher quality is needed to validate these significant results and draw final conclusions. No firm conclusions can be made in mandibular reconstruction and cranioplasty, since no outcomes were significant in favour of either technology. No statements regarding long-term safety outcomes can be made.