The effect of azadirachtin on the development and mortality of the scuttle fly, Megaselia scalaris (Loew) (Diptera: Phoridae) was investigated in the laboratory by using neem extract, Achook^®, containing 0.15% azadirachtin. Different biological changes were recorded after treatment 1^st larval instar with different concentrations of azadirachtin as larval mortality, pupation rate and adult emergence of. Azadirachtin-LC₅₀ against the 1^st instar larvae of M. scalaris was 13.79 mg/L. Exposing larvae to LC₅₀ of azadirachtin caused many changes in the puparia such as having folded cuticle and swelling of the integument compared to control. Distortion of the anterior spiracle and papillae found on respiratory horns were also observed. The present study suggests that azadirachtin hampers the development rate of M. scalaris by reducing the insect population and causing several scanning electron microscopic changes in the puparia of the insect.