The kinetics of condensation of octamethyltetrasiloxane-1,7-diol, tetradecamethylheptasiloxane-1,13-diol, and the mixture of oligo(dimethylsiloxanediol)s H(OSiMe(2))(n)OH (n = 4-19) catalyzed by trifluoromethanesulfonic (triflic) acid were studied in dichloromethane solution. Rates of cyclization and linear growth of various siloxanediols were compared. The conversion rate decreases with the length of siloxane chain up at least 9 SiO units in the molecule. Complex kinetic dependencies indicate that the mechanism of silanol condensation catalyzed by triflic acid in dichloromethane is complicated by the equilibria involving acid, silanol, and water. The scope of operation of the mechanism involving basic assistance by a silanol group (intra-inter catalysis) in the condensation of silanols is discussed.