Solvent extraction experiments are carried out in a t-junction serpentine microchannel and a split-and-recombine microchannel with TBP-nitric acid system. Stripping experiments have been carried out in the t-junction serpentine microchannel. The effects of residence time and O/A ratio on overall volumetric mass-transfer coefficients are discussed. Flow patterns in microchannels are observed to have more insight into experimental trends. For the same average velocity, the split-and-recombine microchannel is found to give higher overall volumetric mass-transfer coefficient. Overall volumetric mass-transfer coefficients observed for the two microchannels are compared with overall volumetric mass-transfer coefficients reported for conventional extractors.