Technical Abstract: Scirtothrips dorsalis (Hood) is an emerging pest of numerous economically important vegetable and ornamental crops in Florida. Since its advent in 2005, it has rapidly dispersed across the state and is causing significant damage to horticultural and nursery production statewide. A comparison of morphometric traits of S. dorsalis populations from different geographical regions was used to study the morphological variation of this species. Specimens of S. dorsalis were obtained from five different geographical regions: New Delhi, India, Shizouka, Japan, St. Vincent, Negev, Israel and Florida, United States of America. Fourteen morphometric characters of each population were analyzed and compared among the five populations. No significant differences were observed between body lengths of the various S. dorsalis populations which ranged from 0.83 mm (Negev) to 0.98 mm (Florida). Data on the measurements of S. dorsalis from each region were also compared with a report from New Delhi, India (1976) to analyze any change in their body sizes during the last three decades. Apparently the mean body lengths of adults from each population are greater than the reported study (0.76 mm) with all other measurements being comparable. No significant differences were detected between antennal length, head length or width, prothorax length or width, and the lengths of the ovipositor, forewing and hindwing among any of the populations evaluated. However, the mesothorax and the metathorax length and width of the Japan population were significantly larger than the Florida population. The Japan population mesothorax width and metathorax length was also significantly larger than the Israel population. The population from St. Vincent metathorax and abdomen widths was significantly smaller than the Japan population. Together these measurements indicate that the Japan population was significantly larger than the other populations.