Pulsed laser polymerization experiments with methyl and dodecyl methacrylate were carried out at various frequencies and temperatures. In addition, the temperature inside the polymerization cell was continuous and automatically registered all along the polymerization time by means of a temperature probe of rapid response time. A significant increase in the reaction temperature was observed for most of the experiments. The temperature profile during the experiments was dependent on the chemical structure of the monomer and on the pulse repetition rate (the higher increase in temperature, the shorter the time between successive laser pulses). The analysis of the well-structured molecular weight distributions of the resulting polymers by size exclusion chromatography (SEC) allowed the determination of the propagation rate coefficients, k(p). The k(p) values showed a decreasing trend when the pulse repetition rate did so. This effect is nowadays being discussed in terms of a long-range chain length dependence of k(p) (molecular weights at the first inflection points in the SEC traces were always higher than 100 monomeric units). However, the changes in k(p) for different pulse repetition rates could be adequately explained by considering the increase in temperature in every PLP experiment.