The effect of harvesting times on growth, yield and quality of kalmegh were investigated. The results were disclosed that for three local kalmegh cultivars, stem and leaf dry weight and total dry weight of Prachinburi cultivar were the the highest and followed by Nakhon Prathom and Pitsanulok 5-4 cultivars, respectively. Leaf dry weight and seed dry weight yield of Prachinburi cultivar were the highest. Harvesting times affected on growth and yield of kalmegh. The highest leaf dry weight yield (13.59 g plant <sup>-1</sup> ) and andrographolide content (2.54%) were recorded at harvesting times of 135 DAP but the highest seed dry weight yield was detected 170 DAP. However, it is recommended that harvesting times at 135 DAP in Prachinburi local kalmegh cultivar should be adopted.
