Analysis of in silico stereoelectronic properties of PMD (p-menthane-3-8-diols) and its derivatives to develop a pharmacophore for insect repellent activity PMD, an insect repellent that can be derived from steam distillate residue of leaves of lemon eucalyptus. No QSAR studies are known in literature. We performed ab initio (RHF/6-31G**) study of PMD derivatives. A 3D pharmacophore for repellent activity was also developed. Results indicate lipophilicity, MEP separation and localized negative MEP by oxygen atom have roles for repellency. The pharmacophore is consistent and allowed design of more effective insect repellents.