Schwannoma is a benign tumor located in the Schwann cells of the nerves. A 36-year-old white man underwent surgery after being diagnosed with radial nerve schwannoma of the upper right extremity between the triceps brachii muscle and brachioradialis muscle, after which a complete axonotmesis of the aforementioned nerve trunk occurred. The symptomatology presented by the patient included a loss of both motor and sensory function of the fingers, hand, and right forearm. The treatment was a biobehavioral physiotherapy approach that included therapeutic exercise, neuro-orthopedic manual physical therapy, therapeutic education, and sensitivity retraining. The biobehavioral approach in physiotherapy includes a multimodal approach that encompasses biological aspects, along with cognitive-evaluating and motivational-affective components. Two weekly sessions were held for 6 months, resulting in a total of 48 sessions. Using multimodal physiotherapy based on a biobehavioral approach, after 6 months of treatment, the symptoms improved. The motor function of the upper limb improved considerably due to the recovery of increased activity of the superficial musculature dependent on the radial nerve. However, the functions dependent on deep forearm and hand musculature recovered to a lesser extent. At the sensory level, the retraining of sensitivity allowed the patient to regain an important sensitivity. This case report explains the treatment used and the findings obtained, given a large percentage of the functionality that had been lost was recovered.