Using electromagnetic treatment, a detailed analytical investigation of stimulated Brillouin scattering (SBS) has been made for a semiconducting crystal in the presence of an external magnetostatic field. The effect of piezoelectricity (β) and magnetic field [Formula: see text] has been introduced through equation of motion of lattice vibration and Lorentz force, respectively. The analysis is applied to both cases viz. non-piezoelectric (β = 0) and piezoelectric (β ≠ 0) in the absence (B0 =0) and the presence (B0 ≠ 0) of external magnetostatic field. The numerical estimates are made for n-type InSb crystals, taken as representative III–V semiconductor, duly shined upon by pulsed 10.6 μm CO 2 laser. The inclination of applied magnetostatic field with respect to the direction of propagation of pump beam is found to augment the gain coefficient for the onset of stimulated Brillouin scattering. Moreover, the SBS gain coefficient increases with increasing scattering angle and results in a maximum value for the backscattered mode. The backward Brillouin gain is found to be nearly 104 times larger than forward gain when β ≠ 0 and B0 = 10T. The analysis also suggests the possibility of observing optical phase conjugation reflectivity as high as 106 in the weakly piezoelectric doped semiconductors with moderate magnetostatic field. The numerical estimation suggests that piezoelectric doped III–V semiconductors in the presence of magnetic field are candidate materials for fabrication of cubic nonlinear devices.