Axial mixing phenomena in pulsed sieve plate liquid-liquid extraction columns have been studied using the stationary phase tracer technique. Based on 270 data points and covering a wide range of column geometry, the following correlation was obtained : E(0) = a(rho(c)d(0)fA/mu(c))(-0.3)(fA)(1 -e(2))D-1.33/(he(2)C(D)(2))(0.33)+b(fA(2)/e(2))(h/a)(0.45),m(2)s(-1) The above two-term correlation was found to be necessary in order to distinguish axial mixing effects close to the plates and those in the main body of the column compartments, the latter effect becoming dominant as plate spacing increases. The preconstant ’a’ was found to be approximately in inverse proportion to the column diameter D, possibly due to wall effects, whereas the preconstant ’b’ was approximately constant. The axial mixing was found to be at a minimum for plate spacings in the range of 45 to 80 mm and the large increases in axial mixing for plate spacings outside this range help to explain the lack of agreement in the correlations of previous workers. The form of the correlation (with proper dimensions) suggests that the functional dependence of axial mixing coefficient on amplitude and frequency of pulsation varies from fA to fA(1.5), according to the relative magnitudes of the two terms. The effect of column diameter, for column diameters from 40 to 152 mm examined in this work, is found to vary from about D-0.3 to D-1. The effects of plate voidage e, plate spacing h and plate hole size d(0) are now well-represented over wide ranges, as well as the effects of viscosity. The stationary phase tracer technique employed in this study provided a very convenient and adequate means of study and led to results that are in good agreement with those of other single phase measurement techniques.