Dispersion polymerization kinetics of styrene was investigated in this study. A monomer phase soluble initiator, namely lauroyl peroxide, and a water phase soluble emulsifier, namely sodium dodecyl sulfate, were used. The polymerizations were carried out in a magnetic drive, sealed, cylindrical polymerization reactor, in nitrogen atmosphere. Two different fatty alcohols, cetyl and lauryl alcohols, were tried as particle size increasing agents. The effects of initiator, emulsifier concentrations, monomer/water ratio, and the weight ratio of particle size increasing agent to emulsifier on the total monomer conversion, average size, and size distribution of the large latex particles were studied. The agglomeration conditions were tested by changing the polymerization temperature, initiator, and emulsifier concentrations. The results indicate that the polymerization rate and the average size of the latex increased with increasing emulsifier concentration. The average size of the latex was also increased with increasing initiator concentration. The use of cetyl alcohol in the presence of emulsifier resulted in an appreciable increase in the polymerization rate and in the average size of the latex. The effect of fatty alcohols on the polymerization rate in the dispersion polymerization system was completely different than that in the swollen emulsion polymerization. The agglomeration of the large latex particles was increased with decreasing emulsifier and increasing initiator concentrations.