Vinca rosea is a plant renowned for its medicinal value, belonging to the family Apocynaceae. Traditionally, the leaf juice of V. rosea is used for treatment of various diseases. In the present study, the effect of V. rosea leaf extract on the development of Drosophila melanogaster has been investigated. Different concentrations of leaf extract (1%–12%) have been used, and feeding the flies with food mixed with the leaf extract resulted in a significant developmental delay, several phenotypic anomalies such as larval/pupal lethality, eye defects, wing defects, and reduction in body size. Further, immunochemical staining for the ecdysone receptor (EcR staining) of salivary glands of larvae showed a significant reduction in EcR expression, suggesting that developmental delay was associated with reduced expression of the receptor protein. Thus, the present study suggests an insecticidal activity associated with V. rosea.