The ionization potentials and cohesive energies of small Ge-n and Sn-n (n=2-13) clusters have been calculated using the semiempirical tight binding total energy method. Matrix elements were obtained from the Slater-Koster terms using the universal parameters of Harrison. The structures of clusters were determined by adopting well-known shapes and adjusting the bond lengths using our total energy scheme. The calculated ionization potentials of Ge and Sn clusters are in reasonably good agreement with the recent experiment and are found to exhibit the characteristic features of experimental data. The calculated cohesive energies are in very good agreement with the experimentally observed data for both Ge and Sn clusters.