A new quantitative model is developed which describes the kinetics and mechanism of transport of a weak organic acid derivative through an integrated solvent/carrier supported liquid membrane (SLM). The transport model is based upon simultaneous occurrence of both mobile and fixed-site jumping carrier mechanisms, and incorporates the assumption of diffusion-limited transport. The theoretical model is verified by comparison with experimental data obtained from a facilitated transport study of ethyl lactate through a supported amine functionalized polyorganosiloxane SLM. The transport parameters, which include the product of solute partition coefficient and diffusion coefficient (KpDs), the equilibrium extraction constant (K-ex), and the effective diffusivity of solute-carrier complex due to both mobile and jumping carrier mechanisms (D-m+D-j), have been determined, and excellent agreement is achieved between predicted and experimental data in most of the studies.