Nonisothermal and isothermal cold crystallization behaviors of poly(p-dioxanone) (PPDO) were investigated by differential scanning calorimetry (DSC). There were two crystallization exotherms-a major exotherm between 25 degrees C and 50 degrees C and a minor one almost unchanged at 77 degrees C with various heating rates-in the heating scans of PPDO during nonisothermal cold crystallization. Temperature-modulated differential scanning calorimetry (TMDSC) revealed the major crystallization exotherm in the low-temperature range to be the real cold crystallization peak, and the minor one in the high-temperature range to be the melt, recrystallization peak of crystals with lower thermal stability. Several methods, including the Avrami, Tobin, and Ozawa equations, were employed to analyze the nonisothermal cold crystallization kinetics of PPDO. The efficiencies of the Avrami and Tobin methods were compared, and the results suggest that the Avrami equation is more suitable for describing nonisothermal cold crystallization kinetics of PPDO. The activation energy for nonisothermal cold crystallization of PPDO was calculated to be 35.27 kJ/mol, using the Kissinger method. In addition, the Avrami equation was also used to describe the isothermal cold crystallization kinetics of PPDO.