We report on the detection of 167.8 +/- 0.2s pulsations from AX J0052.9-7157 in the Small Magellanic Cloud with ASCA. The pulsations show an energy-independent sinusoidal profile. The X-ray spectrum has been described by an absorbed hard power-law (photon index similar to 0.7) with a luminosity of similar to 8.8 x 10(35) ergs(-1) at a distance of 60kpc. The position is determined to be (R.A., Dec.)(J2000) = (00(h)52(m)59.(s)2, -71 degrees 57 ' 58 "), with an error radius of similar to 30 ". We have found that a variable Be/X-ray binary RX J0052.9-7158 is located within the 30 " error circle, and is also located at the edge of the 10 ' error circle of the 169-s pulsar XTE J0054-720. We therefore conclude that these are the same source, a Be/X-ray binary pulsar.