Experimental studies on the pressure drop in tapered bubble columns using non-Newtonian pseudoplastic liquid have been reported. The effects of different variables such as liquid flow rate, clear liquid height, hole diameter of sieve plate, pseudoplasticity of the liquid on the frictional pressure drop have been investigated. The ANN with multilayer perceptron (MPL) with one hidden layer and four different transfer functions with backpropagation algorithm were used to demonstrate its applicability in the prediction of the frictional pressure drop. © 2013 Canadian Society for Chemical Engineering.