The reaction kinetics for the acetylation of 1,2-propylene glycol (PG) catalyzed by p-toluenesulfonic acid (p-TSA) were determined using an in situ H-1 NMR method. Both primary and secondary monoacetate esters of PG were observed as well as the diester. The reaction kinetics were characterized as a function of PG to acetic acid (AA) stoichiometry, p-TSA concentration, and temperature. The acetylation reactions and the transacetylation of the diester with PG were modeled as reversible second order reactions. Equilibrium constants were determined experimentally for each reaction. Activation energies for the consecutive acetylation of PG and PG monoacetate ester (PGMA) were 56 and 47 kJ/mol, respectively. The activation energy for intermolecular transacetylation of PG with its diacetate ester to form PG monoacetate was 63 kJ/mol.