Abstract: A study of the insect biodiversity was performed in Karkheh Wild Life Refuge, SW Iran. Insects were collected during May to October in 2010 to determine their diversity, species richness and evenness. Species were sorted into morphospecies and classified to the lowest taxonomic level possible. A total of 2207 specimens were captured using different sampling methods e.g., netting, beating, hand picking, and trapping. Specimens belong to 100 species, 47 families and 13 orders of insects. Based on the data collected, Coleoptera, with 32 species and highest diversity index of H' = 0.318, were the most diverse and abundant order among collected insects. The staphylinid beetle Achenium debile (Erichson) was dominant species, with relative abundance of 23.9%. The bug Pyrrhocoris apterus Linnaeus was ranked as second dominant species, with relative abundance of 8.4%. Dermaptera and Ephemeroptera, each of them with 1 species, had the least species number compare to other orders. The overall insect biodiversity indices of Shanon-Wiener and Simpson were 3.286 and 0.91, respectively. Evenness was 0.7, using Pielou's index. Overall biodiversity indices show relatively high biodiversity in the area. These data provide a baseline for other studies on wild life refuges of SW Iran.