The physical properties of the III-V semiconducting compounds, GaP, GaAs, and GaSb, have been calculated by employing a scalar relativistic version of the first-principles full-potential self-consistent linearized-muffin-tin-orbital method. The calculated values of the lattice parameters of the compounds are reproduced well within 2.6% of the measured values. The computed dispersion curves and the electronic density of states are in excellent agreement with the available photoemission data for all the compounds. The predicted bulk modulus and the elastic constants are in close agreement with the experimental data where available. The frequencies of the frozen phonons at symmetry points are in good agreement with the available measured data.