The Valence-Shell Electron-Pair Repulsion (VSEPR) theory is a widely used model in chemistry that predicts the geometry of molecules based on the number of electron pairs that surround the central atom. This theory operates on the fundamental principle that the valence electron pairs present around the central atom tend to repel each other. Therefore, the molecule takes on a shape that minimizes this repulsion, thus determining its overall structure. This lecture provides an in-depth exploration of this topic and highlights the crucial role played by molecular shapes in various chemical reactions and biological functions.