Occurrence of fire is inevitable in the Selous Game Reserve which is among the UNESCO world Heritage sites. Apart from prescribed burning, un-prescribed burning was observed to occur in this reserve which was anticipated to deteriorate the wildlife species including insects. This study aimed at determining the impacts of fire on insects of the Selous. Pitfall traps were used in the collection of insects samples in the three designed study sites namely; burnt grassland, un-burnt grassland and burnt woodland. The findings showed that, fire had significant (what level of significance) impacts on diversity and not on abundance of insects. High diversity was observed in un-burnt grassland than in the burnt grassland. However it was eminent that, habitat heterogeneity had significant impacts on both diversity and abundance of insects. Higher diversity and abundance was observed in woodland habitat than in grassland. It was recommended to adhere with the principles of prescribed burning while enforcing laws on illegal sources of fire such as poaching.