The nonresonant third-order hyperpolarizability of all-carbon molecules C60 is measured by nanosecond degenerate four-wave-mixing experiment in C60 toluene solution. The value of gamma(1111) measured is 1.6 X 10(-31) esu, which corresponds to an estimated value of the third-order nonlinear optical susceptibility chi(1111E)(3) = 3.3 X 10(-9) esu for the solid compound.