This paper describes the performance evaluation of distillation-cum-greenhouse for a warm and humid climatic condition. Numerical computations have been carried out for a typical day in January for Chennai, India. Various temperatures, namely plant and water, as a function of climatic and design parameters, were obtained by solving coupled single-order differential equations using the Runge-Kutta method. Room air, transparent cover, basin liner temperature and distillate output were also worked out by using the value of plant and water temperature. Analysis showed that there is a significant effect in the plant, water temperatures and distillate output due to a change in the fraction of the solar radiation incident on the north wall (F-n), depth of water, alpha(b) and the inclination of the roof whereas the heat capacity of the plant has a marginal effect on these temperatures and distillate output. The study revealed that vegetables can be grown in a warm and humid climate in a coastal region by the construction of a distillation-cum-greenhouse unit.