Polarization-resolved forward degenerate four-wave mixing (DFWM) in a nonresonant region revealed the effective third-order nonlinear susceptibility of colloidal CdTe nanocrystals (NCs) with the size near the Bohr radius and various concentrations. The second hyperpolarizabilities, and , of the CdTe NCs were similar to 1.15 x 10(-41) m(5)/V-2 and similar to 3.01 x 10(-42) m(5)/V-2 from the measurement of the concentration-dependent third-order nonlinear susceptibility of CdTe NCs, respectively. The ratio (/) of the hyperpolarizabilities was similar to 0.26, which indicated a large contribution of an electronic polarization process to the third-order nonlinearity of CdTe NCs. (C) 2007 Elsevier B.V. All rights reserved.