Among the various approximations for the noncentral-Fdistribution. the best known are the computationally simpler approximation due to Severo and Zelen [18] and Laubscher [9], which requires only the normal distribution, and a more accurate approximation due to Tiku [21], which requires theFdistribution. Thcsr approximations are systematically evaluated. Some variations of these approximations are considered and found to he of comparable accuracy. An Edgeworth-acries approximation, which requires only the normal distribution, is developed and sren to be superior in accuracy. A FORTRAN-subroutine for the Edgeworth-series approximation is given.