Itaconic acid finds a place in various industrial applications. It can be produced by biocultivation in a clean and environment friendly route but recovery of the acid from the dilute stream of the bioreactor is an economic problem. Reactive extraction is a promising method to recover carboxylic acid but suffers from toxicity problems of the diluent and extractant employed. So there is need for a non-toxic extractant and diluent or a combination of less toxic extractants in a non-toxic diluent that can recover acid efficiently. Effect of different extractants: tri-n-butylphosphate (TBP) (an organophosporous compound) and Aliquat 336 (a quaternary amine) in sunflower oil was studied to find the best extractant-sunflower oil combination. Equilibrium complexation constant, KE, values of 1.789 and 2.385 m(3) kmol(-1), respectively, were obtained for itaconic acid extraction using TBP and Aliquat 336 in sunflower oil. The problem of toxicity in reactive extraction can be reduced by using a natural non-toxic diluent (sunflower oil) with the extractant. (C) 2010 Society of Chemical Industry