The thermal performances of a solar still of a new type are analysed. The still is made of a flat plate heater coupled with an evaporator-condenser recently studied by the same authors (Njomo D, Tchinda R, Kaptouom E. J. Solar Energy Engng., Trans. ASME 1996;118(3):177). The theoretical solar still productivity is in reasonably good agreement with the experimental distillation yields, reported in the literature for heat exchange fluxes less than 1 kW/m(2) usually encountered in solar stills.