The main objective of this paper is verifying the feasibility of using Raman spectroscopy for online monitoring of suspension polymerization reactions. Whether the Raman spectra are affected by the particle size distribution (PSD) is also investigated. It is shown that it is possible to estimate the evolution of conversion during suspension polymerization from Raman spectra collected with the probe connected to the reactor window with a short acquisition time. Results also indicate that monitoring by Raman spectroscopy may allow identification of abnormal behavior during suspension polymerization reactions with the formation of unexpected PSD. Furthermore, results suggest that Raman spectroscopy probably has the potential to infer the PSD of suspension polymerizations because the Raman spectrum is affected by the PSD.