The collisional widths of five emission lines arising from the 2p53p-2p55s transitions in neon perturbed by neon and helium have been measured. The values of the pressure broadening coefficient were determined and compared with the results of calculation based on the impact theory assuming the V(r) = ℏC12r-12 - ℏC8r-8 - ℏC6r-6 interaction potential. These results provide an evidence that the repulsive forces between atoms are very important in line broadening by neon and helium. © 1979.