The insecticidal potentials of plant oil from neem (Azadirachta indica) seeds and wild basil (Ocimum suave) leaves was applied as individual oils and mixed equal proportion (50:50) against adult house flies (Musca domestica). The experiment was setup on a completely randomised design using two replicates per concentration's formulation. Oils from the extracts of Azadirachta indica and Ocimum suave were formulated as emulsifiable concentrates at 0.005, 0.010, 0.015, 0.20/50 ml of water, and then sprayed on 15 newly emerged reared adult house flies in cages at an hour interval for six hours. There was significant difference (P < 0.05) in the percentage mortality of adult house flies as the concentration increased from 0.005–0.20/50 ml water of both the single formulations (A. indica and O. suave) and the equally mixed 50:50 ratio. There was also significant difference as the time of exposure increased from the first hour to the sixth hour. The concentration of A. indica and O. suave required to cause 50 % mortality of adult house fly was 0.066/50 ml water at 3.4 h and 0.072/50 ml at 3.8 h, respectively, while the concentration of the mixed oils at equal proportion (50:50) required to cause 50 % mortality of house fly was less (0.065/50 ml water) and at 3.4 h. This study has therefore revealed the potency of the plant oil extracts (A. indica and O. suave) as single and mixed at equal proportion (50:50) against house fly (M. domestica). However, the formulation of the mixed plant oil required to cause 50 % mortality of the house fly was less, showing higher potential over the single formulations. Therefore using the mixed plant extracts is recommended for the proper management of house fly.