Equipment is described for impact testing of yarns longitudinally and also transversely. The impact velocities range from 1000 to 10,000 ft per min. The corresponding rates of straining at impact range from 50,000 to 500,000 per cent per min for textile yarns. The impact events are recorded with a high-speed motion picture camera. Procedures are discussed for obtaining load-elongation curves for loading and for unloading of the specimen and for loading to rupture in a time interval of only a few milliseconds. Results are presented for a high-tenacity nylon yarn and for two high-tenacity regenerated cellulose yarns, Fortisan and X-36, when tested at rates of straining ranging from 1 to 400,000 per cent per min. The effects of rate of straining on the results are discussed.