Melt polymerization conditions for D,L-Lactide initiated with tetraphenyltin were studied with regard to polymer molecular weight. The combined effect of time and temperature on polymer molecular weight and degree of conversion of D,L-Lactide is described. Polymerization at constant initiator concentrations resulted in a narrow scattering of reproducible molecular weight values. The presence of air/moisture and other impurities during the melt polymerization most likely have a deterimental effect on molecular weight. After a short induction period the rather slow polymerization of D,L-Lactide resulted in a maximal molecular weight followed by an almost constant value of molecular weight.