The electronic band structure, density of states and the behaviour of conduction and valence bands in body-centered cubic rubidium and cesium, particularly under varying pressure conditions are studied. The research examines how rubidium’s and cesium’s lattice constant and pressure change with reduced volume, providing insights into its structural properties. Furthermore, the distribution of electron energy levels is analysed through the density of states across different energy regions. The conduction and valence band widths are calculated relative to the Fermi level and mapped across key symmetry points in the Brillouin zone.