The characteristics of high speed bubbly flows through convergent-divergent nozzles are studied theoretically. A steady, one-dimensional flow is considered. The liquid phase is water, whereas the gaseous phase consists of a mixture of both non-condensable (air) and condensable (water vapor) components. The comprehensive physical model allows for momentum and thermal lags as well as mass transfer between the gaseous and liquid phases due to evaporation and condensation. The parametric analysis reveals that choked flow with supersonic speeds along the diverging section of the nozzle, similar to the behavior of a compressible gas flow, may be obtained under appropriate conditions. Effects of flow parameters such as wall friction, interphase heat transfer, initial bubble size and void fraction are demonstrated. (C) 2003 Elsevier Science Ltd. All rights reserved.