The transalkylation of diethylbenzenes with benzene was studied in the liquid phase, using a p-zeolite as the heterogeneous catalyst. The effects of the main reaction parameters: temperature, contact time and feed composition on catalytic performance were investigated to (i) determine relationships between the formation of the different products, and (ii) find the best reaction conditions. Ethylbenzene was found to form via both the direct reaction of diethylbenzenes transalkylation with benzene, and consecutive reaction on 1, l-diplienylethane. In addition, ethylbenzene undergoes consecutive cracking reactions, which are favored at temperatures above 270 degreesC.