(1) Background: Patients with head and neck cancer are treated by ablative surgery, radiotherapy, chemotherapy, or a combination of these. The side effects of cancer therapies can compromise conventional prosthesis rehabilitation; therefore, dental implants can result in a more effective solution. The aim of the study is to explain how to rehabilitate a patient that underwent head and neck cancer therapy. (2) Methods: This retrospective study conducted from 2015 to 2021 included 223 postoncological patients, aged between 32 and 80 years old. Eighteen patients did not proceed with any treatment, and two died. Therefore, 203 patients have been analyzed and rehabilitated following our decisional protocol, with a mean period of follow-up of 4 years. The implant placement was considered successful when a mean bone loss of 1.6 mm for the first year and a mean of 0.13 mm in subsequent years occurred (3) Results: A total of 161 patients were rehabilitated with a conventional prosthesis, 42 patients (F:M ratio 19:23) with an implant-supported prosthesis and a total of 200 implants were placed; 9 implants were lost (4.5% of 200 implants). Conclusions: The results confirmed that by following our protocol it is possible to obtain an acceptable rate of implant survival, considering the delicacy and complexity of post-oncological patients.