A novel type of multiple emulsions which contain a microemulsion in macrodroplets, was prepared by a two-step emulsification procedure. Mineral oil was used as the oil phase with a mixture of Aerosol OT and Span 20 as primary emulsifiers. A water-in-oil microemulsion was prepared by gradual addition of water in oil containing both these emulsifiers. This microemulsion system, when dispersed in an aqueous solution containing secondary emulsifier, produces water-in-oil-in water(W/O/W) multiple emulsions. The release rate of solute dissolved in the internal aqueous phase was measured using the dialysis technique. A theoretical model describing the diffusion of a multiple emulsion system was developed, which predicts the half-life for 50% of the internal solute to diffuse to the external phase. Experimental results showed the stability of multiple emulsions improved significantly upon using a thermodynamically stable micro-emulsion as a primary emulsion and a polymeric surfactant as a secondary emulsifier. As a result, half-life of these multiple emulsions is greater than that of conventional multiple emulsions.