The technique of pulsed laser photolysis/pulsed laser-induced fluorescence was used to determine products of the following reactions: OH + CH3SCH3 → products (1) and CH3S(OH)CH3 + O2 → products (5). The non-adduct-forming channel of reaction 1 was observed to proceed via hydrogen abstraction (branching ratio, Φabs = 0.84 ± 0.26) at 298 K. Direct formation of CH3S from reaction 1 was not observed (ΦCH3S < 0.04). A small channel for producing CH3 and CH3SOH in the non-adduct-forming route could not be ruled out. HO2 was found to be produced from reaction 5 with a yield of 0.50 ± 0.15 at 234 and 258 K. An upper limit for the production of OH from reaction 5 was determined to be ΦOH < 0.05. The atmospheric implications of the results from this and the accompanying paper are discussed.