Hi-Tech agricultural systems is nothing but better management and utilization of existing resources so as to be able to meet the need of the rapidly growing population by producing more output per unit of resource used. Greenhouse is one of the Hi-Tech agricultural systems wherein plants are grown under controlled or partially controlled environmental conditions resulting into higher yields than that possible under open conditions. In addition to this, it is one such technology, which provides immense potential for youths and persons interested in agribusiness. Properly designed, oriented and constructed greenhouse can provide ventilation rates comparable to the rates provided by mechanical ventilation to have an optimum temperature. In this study an attempt was made to design and develop a naturally ventilated greenhouse suitable for tropical climate of Coimbatore district. The study evaluated the effect of height of the greenhouse (3m, 3.75m, 4.5m) and various roof (0%, 3%, 6%) and side (5%, 10%, 20%, 25%, 30% and 35%) ventilations on microclimate. The effect of microclimate on the growth and yield parameters of cauliflower (Namdhari NS 60) was also studied.