A titration procedure using immediate-release morphine given 4-hourly is recommended during start of oral morphine for cancer pain. This recommendation is not based on evidence from controlled studies, and many physicians start morphine treatment with controlled-release morphine. We included 40 patients with malignant disease and pain despite treatment with opioids for mild to moderate pain in a randomized, double-blind, double-dummy, parallel-group study comparing titration with immediate-release morphine given 4-hourly with titration with sustained-release morphine given once daily. The primary end point was the time needed to achieve adequate pain relief Secondary end points were other symptoms (nausea, tiredness, lack of sleep, vertigo, appetite and constipation), health related quality of life and patient satisfaction. The mean times needed for titration were 2.1 (95% CI; 1.4-2.7) days using immediate-release morphine and 1.7 (95% CI; 1.1-2.3) days using sustained-release morphine. Patients titrated with immediate-release reported statistically significant more tiredness at the end of titration. We observed no other differences in adverse effects or health related quality of life functions between the two treatments. Similar global satisfactions with the morphine treatments were reported. In conclusion, a simplified titration using sustained-release morphine once daily is equally effective as immediate-release morphine given 4-hourly.