In this article, we describe our experience with oral morphine for the treatment of patients with cancer pain who were referred to a Palliative Care Unit. Morphine was used in 3,399 days treatment with an average of 65 days per patient. In 50 patients (96%), there was a decreased intensity of pain from severe (Visual Analogue Scale average (VAS) 8.7) to mild (VAS average 1.9). Daily average dose was 95.6 mg. Only 26 patients (50%) required an increase in dosage. The side effects were minimal and controllable. Even though most authors recommend morphine q4h, in our population q6h was enough to achieve pain control in 83% of patients. It should be known by the medical population that morphine is essential therapy for pain in cancer patients. This study confirms that morphine is an excellent drug for the control of pain in cancer patients, with minimal dosages and controllable side effects.