The ultrafast nonlinear optical response of C-60-polystyrene n-arm (n = 3,6) star polymers in toluene solution is studied using the optical Kerr effect technique under excitation with 800 nm, 100 fs laser pulses. Their response is found to depend on the number and the molecular weight of the arms and to be much larger than that of pure C-60. Finally, the second hyperpolarizability of the C-60-polystyrene n-arm star polymers is determined.