A 10‐Hz coherent anti‐Stokes Raman spectroscopy (CARS) instrument capable of simultaneous thermometry and N2‐concentration measurements in a turbulent flame has been designed and constructed and is described in detail. The instrument employs the doubled output of a pulsed Nd:YAG laser for pumping a broadband dye laser and also for the CARS pump beam. The broadband dye laser is used to excite, during a single pulse, the entireQBranch of N2, the CARS signal of which is recorded by a multichannel analyzer. Special problems which were encounted with the multichannel analyzer include signal retention and limited dynamic range. The former was greatly reduced by employing cleansing scans between laser firings, and the latter was circumvented by employing a multiple beamsplitter arrangement in which the CARS signal was divided into four separate intensity regions, each of which covered a specific temperature range. The 10‐Hz operation of the instrument required the use of a mass storage device such as an 800‐bits‐per‐inch tape. CARS data recorded and digitized by the multichannel analyzer were transferred via machine‐coded instructions to a minicomputer for storage on tape. Analysis of the CARS data consisted of a nonlinear least‐squares fit of the CARS bandshape for thermometry and integration of the CARS signal for N2concentrations. CARS measurements in a near‐stoichiometric premixed propane flame and a turbulent diffusion flame are reported. Results of calibration measurements indicate that uncertainties of 4% in temperature and 6% in concentration are obtainable with this instrument.