Rate coefficients, k(1)(T), over the temperature range of 210-390 K are reported for the gas-phase reaction OH + HC(O)C(O)H (glyoxal) -> products at pressures between 45 and 300 Torr (He, N-2). Rate coefficients were determined under pseudo-first-order conditions in OH using pulsed laser photolysis production of OH radicals coupled with OH detection by laser-induced fluorescence. The rate coefficients obtained were independent of pressure and bath gas. The room-temperature rate coefficient, k(1)(296 K), was determined to be (9.15 +/- 0.8) x 10(-12) cm(3) molecule(-1) s(-1). k(1)(T) shows a negative temperature dependence with a slight deviation from Arrhenius behavior that is reproduced over the temperature range included in this study by k(1)(T) = [(6.6 +/- 0.6) x 10(-18)]T-2[exp([820 +/- 30]/T)] cm(3) molecule(-1) s(-1). For atmospheric modeling purposes, a fit to an Arrhenius expression over the temperature range included in this study that is most relevant to the atmosphere, 210-296 K, yields k(1)(T) = (2.8 +/-0.7) x 10(-12) exp[(340 +/- 50)/T] cm(3) molecule(-1) s(-1) and reproduces the rate coefficient data very well. The quoted uncertainties in k(1)(T) are at the 95% confidence level (2 sigma) and include estimated systematic errors. Comparison of the present results with the single previous determination of k(1)(296 K) and a discussion of the reaction mechanism and non-Arrhenius temperature dependence are presented.