Extraction in liquid-liquid segmented flow is used for preconcentration of indium from dilute nitric acid solutions into bis(2-ethylhexyl)phosphoric acid dissolved in 4-methylpentane-2-one. The extraction setup is coupled on-line with flame spectrometry to give a fully mechanized system. The detection limit of the method is 0.03 mg l-1, the calibration plot is linear up to 1.75 mg l-1. Repeatability is 1.5% RSD measured at 1 mg l-1. Sample throughput is 60 h-1. © 1987.