The use of pulse coding (or pulse comprehension) in radar to obtain improved detection of targets in clutter is discussed. The effectiveness of this technique depends on the differing spatial characteristics of the target and clutter in contrast with the usual MTI which depends on the differing time- varying properties. With the assumptions of a simple clutter model and an appropriately optimized receiver, and with the aid of known results in detection theory, an expression is derived or the single-pulse detection capability of a radar operating in the presence of both clutter and additive white receiver noise. From the expression it is seen that detection performance is simply related to the spectrum of the transmitted signal and, generally speaking, improves as the bandwidth of the transmitted signal is increased. Results for clutter noise only or receiver noise only appear as special cases.