Static fatigue tests at liquid nitrogen temperature have been completed on virgin E-glass single filaments. In these tests, fibers approximately 0.0005-inch diameter were dead-loaded in tension while at -196C and maintained at that temperature for at least 48 hours. Loads were varied within the high stress region from 400,000 to 650,000 psi. No static fatigue failures were observed under these conditions, even though the stress range was high enough to cause immediate failure of some fibers upon load application. This is in distinct contrast to the behavior observed at room temperature in normal humidity where delayed failures occurred over several decades of time with stress level ranging from 200,000 to 400,000 psi.