Controlled molecular weight, linear, ortho- and para-cresol novolac oligomers have been synthesized by using calculated amounts of a monofunctional 2,6-dimethylphenol endcapping reagent. It was found that an excess of formaldehyde was needed to achieve the targeted molecular weights, thus suggesting that a dynamic equilibrium exists in these reactions whereby formaldehyde adds and eliminates from the cresol rings. Reaction progression was monitored by both C-13 NMR and GPC. Number average molecular weights of these oligomers were confirmed using 13 C NMR spectra and were found to be comparable to the targeted molecular weights. The glass transitions and viscosities of both the ortho- and para-cresol novolacs were compared at equivalent number average molecular weights. The T(g)s increased as the molecular weights increased, but there were no observable differences between the T(g)s of ortho- and para-cresol novolacs with similar molecular weights. The melt viscosities of ortho- and para-cresol novolcas with similar molecular weights were almost identical.