Transverse eddy diffusivities of dispersed phase drops in a 0.30-m diameter pulsed perforated plate column were determined by two methods involving measurement of changes in local holdup over the column half cross sections, one of which was initially drop free and the transfer of color tracer over the cross sections, in only one of which tracer was present initially. Both methods indicated a relatively low diffusivity of similar to 10(-4) m(2) s(-1) for both emulsion and intermediate regions of operation. However, similar tracer measurements of the radial diffusivity for the continuous phase indicated virtually complete mixing at the inlet stage. It is concluded that the reduced performance of these columns with increase in diameter in previous reports must have been due to initial maldistribution at the dispersed phase distributor at low throughputs, and a proposal is made for a more suitable form of distributor.