The ring-opening polymerization (ROP) of p-dioxanone (PDO) under microwave irradiation with triethylaluminum (AIEt(3)) or tin powder as catalyst was investigated. When the ROP of PDO was catalyzed by AlEt3, the viscosity-average molecular weight (M-v) of poly(p-dioxanone) (PPDO) reached 317,000 g mol(-1) only in 30 min, and the yield of PPDO achieved 96.0% at 80 degrees C. Tin powder was successfully used as catalyst for synthesizing PPDO by microwave heating, and PPDO with M-v of 106,000 g mol-1 was obtained at 100 degrees C in 210 min. Microwave heating accelerated the ROP of PDO catalyzed by AlEt3 or tin powder, compared with the conventional heating method. (C) 2008 Wiley Periodicals, Inc.