Care of patients with cancer can be enhanced by continued involvement of the primary care physician. The physician's role may include informing the patient of the diagnosis, helping with decisions about treatment, providing psychological support, treating intercurrent disease, continuing patient-appropriate preventive care, and recognizing and managing or comanaging complications of cancer and cancer therapies. Adverse effects of therapy and cancer-related symptoms include nausea, febrile neutropenia, pain, fatigue, depression, and emotional distress. 5-Hydroxytryptamine antagonists are effective in controlling acute nausea associated with chemotherapy. Febrile neutropenia requires systematic evaluation and early empiric antibiotics while awaiting culture results. Cancer-related pain, depression, and fatigue often are underdiagnosed and undertreated. Use of brief screening tools for assessing fatigue and emotional distress can improve management of these symptoms. Exercise prescription, activity management, and psychosocial interventions are useful in treating cancer-related fatigue. The physician must be alert for signs and symptoms of cancer-related emergencies like spinal cord compression, hypercalcemia, tumor lysis syndrome, pericardial tamponade, and superior vena cava syndrome.