The paper reported the clinical experience of using pectoralis major myocutaneous flap for the immediate repair of massive defects from excising the oral and maxillofacial malignant tumours in 21 cases from 1985 to 1993. The valuation, design, preparation, technique of transfer of the flap and the prevention of flap from necrosis were discussed. It was suggested that the pectoralis major myocutaneous flap was worth using for the immediate repair of massive defects around oral and maxillofacial regions.