Solvent extraction of La(III) from acidic nitrate medium has been studied with [A336][NO3-] in kerosene. The factors affecting the extraction of La(III) like equilibration time, nitrate ion, extractant and La(III) concentrations, aqueous acidity, O/A ratio variation, nature of diluent, and temperature have been investigated. McCabe-Thiele diagram has been plotted to find out the actual number of theoretical stages needed for complete extraction of lanthanum. The solvent has been successfully regenerated for further use after stripping of the metal. IR studies of [A336][NO3-] and La(III) loaded [A336][NO3-] have been carried out. Modeling of extraction data has been done using Multiple linear regression analysis and Artificial Neural Network, and the performances have been compared. Error in each case was evaluated in terms of R-2 and Root mean squared error (RMSE). Maximum extraction of La(III) was 82% when 0.6 M [A336][NO3-] was used for extraction. About 98% of the metal has been recovered using 0.2 M HNO3 as stripping agent. Extractive separation of La(III) and Sm(III) was maximum (beta = 65.2) using 0.1 M [A336][NO3-]. IR studies revealed formation of lanthanum complex in the extraction process. Artificial Neural Network proved to be better over Multiple linear regression in data prediction.