This work aims to compare between the forensic insect species, their succession patterns and decomposition stages of rabbit corpses killed with different methods in Qena city, Egypt. Four experiments were carried out during this study for four successive seasons. Four rabbits were placed in each experiment, the first two rabbits received a double LD50 of tramadol hydrochloride and cypermethrin via ear vein injection. The third rabbit was slaughtered while the fourth rabbit was euthanized with air injection (control). The LD50 of tramadol and cypermethrin in male rabbit was calculated from logarithmic scale and found to be 132 mg/kg and 126 µǀ/kg body weight, respectively.Currently, a total of 14271 insect individuals were collected from the screened bodies belonging to three orders, thirteen families and seventeen species. Moreover, corpses were colonized by different insect life stages (11689, 352 and 2230 individuals) included dipteran flies, Coleopteran and Hymenopteran insects, respectively The total number of species collected in summer was lower than in other seasons. Tramadolrabbits decayed with similar rate to the control corpses during all seasons except in winter. As well as, decomposition process was significantly prolonged in cypermethrin killed rabbits during all seasons. However, slaughtered carrions decayed faster than control in winter and spring. Maggots deposited on cypermethrin- carrions were very few and have been dead after few days from oviposition. Density of maggots collected from control corpse was loweras compared to the slaughtered and higher than that on tramadol corpse. Therefore, these results are recommended to be taken in criminal investigations.