The separation of lactic acid from complex fermentation broth was examined. Liquid-liquid extraction using reversible chemical complexation for reactive extraction was chosen to be the separation method. Over 50% yield of lactic acid was obtained from fermented broth in a single extraction step, when using the tertiary amine as the extractant, 1-dekanol as the diluent and trimethylamine (TMA) as the stripping solution. The effect of complex media on the extraction behaviour has hardly been examined previously.