Q-Lead is a tool for predicting biological activity of untested or novel phytomolecules/derivatives to provide insight into relevant 2D & 3D chemical descriptors responsible for biological activity. For this, Q-Lead uses various in-house developed local & global Quantitative Structure-Activity Relationship (QSAR) models based on natural compounds. Q-Lead QSAR models quantitatively correlates chemical descriptors (structural properties) with biological activities for a set of similar compounds. Q-Lead QSAR models are developed by using linear statistical methods such as Multiple Linear Regression (MLR) and Partial Least Square (PLS). Q-Lead tool can be used for potential lead identification (screening) and optimization.