Western Ghats is one of the 18 hot spots of the world for biodiversity conservation and protection. Increasing human activities and tourism in forestry and changing life style of humans lead more difficult to solve criminal cases. Blow flies (Diptera: Calliphoridae) are important components of decomposition process of wild and human bodies in forest ecosystems. Biotic and abiotic factors of environment have direct impact on population dynamics of flora and fauna of forensic importance. The blow flies use carrion as a resource for propagation of their own progeny. Therefore, altitudinal diversity of forensic blow flies in Western Ghats has been reported. A total of 19 species of blow flies belonging to the genera Chrysomya, Lucilia and Calliphora have been reported. The genus Lucilia and Chrysomya were abundant at low altitude than higher altitudes of Western Ghats. In general, blow fly diversity decreased with increase of altitudes and qualitative faunal diversity of blow flies were different at different study spots. The outcome of faunal turn over analysis clearly indicated that assemblage at 545 m and 585 m share almost 71.42% of their fauna in common. Also elevation of 900 m shares 70.70% of its assemblage with 585 m. Similarly, assemblage at 42 m and 22 m share about 40% of their fauna in common. The life cycle under laboratory (27 ± 1ºC, 70-80%, 12 hours photo period) ranged from 9-11 days in the species, C. erythrocephala and L. sericata.