Supported Liquid Membranes (SLM) have been developed as a new emerging technology to separate and concentrate diluted compounds from a complex mixture. Specific liquid barriers must be applied to each particular application in order to obtain a selective separation of the valuable solute. The analysis, modelling and design of supported liquid membranes systems are reviewed through the experimentally studied phenol recovery and chromium (VI) separation and concentration. From the results of these works the main characteristics of the stability, mathematical modelling and mass transfer evaluation have been established The stability of the supported liquid membrane depends on the polymeric support and chemical composition of the liquid barrier. An exhaustive experimental evaluation of the stability is necessary before each application. The main instability phenomena are described in the text. The mathematical modelling of the SLM process can be performed using whether lumped parameters or according to the solution of the continuity mass conservation equation and the associated boundary conditions. The development of specific correlations for mass  transfer parameters allows the evaluation of mass transfer rates, stating the basis of design and optimization of Supported Liquid Membrane systems, as it is shown in the text.