Biliquid foams are unique and intriguing systems believed to be structurally similar to foams, although the actual structure is unknown. A distinction is that the gaseous phase is substituted by a liquid phase; such systems were first re-. ported by Sebba in 1972. Potential uses of these biliquid foam systems include personal care products, soil remediation, and controlled release of actives. However, despite the broad range of potential applications, little has been done to clarify Sebba's proposed structure. Indeed authors have proposed that these systems are essentially high-internal-phase-ratio-emulsions (HIPREs). A variety of biliquid foams have been created to study effects such as surfactant identity and concentration on the system, and to map portions of the phase diagram for this complex system. SANS has been carried out at ISIS and the ILL in an attempt to ascertain the underlying structure of these biliquid foams. These results appear to be similar to SANS of purely gaseous foams, although there appears to be only limited evidence supporting the hypothetical "aphron" structure initially proposed by Sebba