The absolute rate constant for the C6H5 + CCl4 reaction, an important reference process employed in numerous kinetic studies in solution, has been measured for the first time with the cavity-ring-down method in the gas phase at temperatures between 298 and 523 K. A weighted least-squares analysis of our gas-phase kinetic data gives k(CCl4) = 10(9.10+/-0.08) exp[-1397 +/- 83)/T] M(-1) s(-1). Our values obtained at 298, 318, and 333 K compare reasonably well with those measured in solution by means of relative product formation and transient kinetic determination.