A diagnostic wax-up is a laboratory procedure in which teeth are created in wax according to a patient’s planned restoration. It may be used to evaluate the feasibility of a proposed plan or to fabricate a radiographic template, a surgical guide, or laboratory guide. In order to complete a diagnostic wax-up, the dental practitioner should carefully and precisely write the wax-up prescription with the details and desired outcome for the technician to replicate. It is then the laboratory’s and technician’s job to ensure that proper tooth alignment, position, and morphology are achieved in the creation of the wax-up. The diagnostic wax-up is an invaluable tool for determining the feasibility of a proposed treatment plan. The model may show that the desired outcome cannot realistically be achieved due to limiting factors that may not be discernible during the examination of the patient. In this way, the diagnostic wax-up prevents unnecessary and unsuccessful procedures from being performed.