An experimental study was conducted on the liquid-liquid extraction of isobutyric acid by means of cumene from its aqueous solutions in an air-operated impinging streams contactor (AOISC) with spray nozzles. Aqueous and organic streams may or may not contact one another inside the spray nozzles depending on the modes of operation. The overall Volumetric mass transfer coefficient, K(L)a, determined enabled us to evaluate the performance capability of the contactor. The effects of air and solution now rates, contactor length and diameter, impingement zone as well as modes of operation have been investigated. These experimental results verify the capability of the method of impinging streams in liquid-liquid extraction.