Recently, the mechanisms leading to the resonant Kerr nonlinearity of Cd(S,Se)‐doped glasses could clearly be assessed. On this basis, we reconsider experimentally the size dependence of the fast component of this nonlinearity. We observe that the figure of merit corresponding to this fast component decreases when the particle size decreases. The various results that had been previously reported are discussed in light of this work. ©1995 American Institute of Physics.