The present study investigated the effects of the accumulation of tramadol on the development rates of the larvae and pupae. Larvae of the flesh fly Sarcophaga argyrostoma (Robineau-Desvoidy, 1830) were reared on three groups of Wister albino rat livers. One group was administere the recommended or normal dose (D1) and the second group was injected with higher over or double dose (D2) of tramadol. Tramadol was administered by stomach tube once a day, for 3 months. The third group was injected with normal saline solution as the control. Using GC-Ms analysis, Rat livers contained 0.72 and 1.62mg/g of tramadol, in case of D1 and D2, respectively. Larvae of S. argyrostoma fed on D1 and D2 rat livers contained (0.11 & 0.18mg/g), respectively. The corresponding tramadol concentrations persisted in the produced pupae of S. argyrostoma were (0.07 & 0.09mg/g), respectively. The accumulation of tramadol in tissues of S. argyrostoma larvae reduced the durations of larval stadia from (7.0408±1.0198 days) in case of the control to (6.6383±0.4857 days) when fed on D1 liver and (6.3438±0.4826 days) when fed on D2 livers. The pupal durations was altered to (14.3750±0.4919 days) for D2 and (14.9574±0.6580 days) for D1, compared to (13.9167±1.0071 days), in case of the control. The average weight of the 3rd day larva of S. argyrostoma decreased from 18.1807±1.4949mg, in case of the control to 14.7279±1.3366mg and 14.9560±3.8210mg, when fed on D1 and D2 tramadol treated livers. In contrast, corresponding weight produced pupae increased from 14.1750±0.4667mg (control) to 15.2449±0.302mg & 15.9062±0.2888mg, in case
of D1 and D2, respectively.