The kinetics of the OH + glyoxal, (HCO)(2), reaction have been studied in N-2 and N-2/O-2 bath gas from 5-80 Torr total pressure and 212-295 K, by monitoring the OH decay via laser induced fluorescence (LIF) in excess (HCO)(2). The following rate coefficients, k(OH+(HCO)2) = (9.7 +/- 1.2), (12.2 +/- 1.6), and (15.4 +/- 2.0) x 10(-12) cm(3) molecule(-1) s(-1) (where errors represent a combination of statistical errors at the 2 sigma level and estimates of systematic errors) were measured in nitrogen at temperatures of 295, 250, and 212 K, respectively. Rate coefficient measurements were observed to be independent of total pressure but decreased following the addition of O-2 to the reaction cell, consistent with direct OH recycling. OH yields, Phi(OH), for this reaction were quantified experimentally for the first time as a function of total pressure, temperature, and O-2 concentration. The experimental results have been parametrized using a chemical scheme where a fraction of the HC(O)CO population promptly dissociates to HCO + CO, the remaining HC(O)CO either dissociates thermally or reacts with O-2 to give CO2, CO2 and regenerate OH. A maximum Phi(OH) of (0.38 +/- 0.02) was observed at 212 K, independent of total pressure, suggesting that similar to 60% of the HC(O)CO population promptly dissociates upon formation. Qualitatively similar behavior is observed at 250 K, with a maximum Phi(OH) of (0.31 +/- 0.03); at 295 K, the maximum Phi(OH) decreased further to (0.29 +/- 0.03). From the parametrization, an OH yield of Phi(OH) = 0.19 is calculated for 295 K and 1 atm of air. It is shown that the proposed mechanism is consistent with previous chamber studies. While the fits are robust, experimental evidence suggests that the system is influenced by chemical activation and cannot be fully described by thermal rate coefficients. The atmospheric implications of the measurements are briefly discussed.