The flux of primary cosmic-ray helium nuclei was measured in nuclear photographic emulsions exposed on a high altitude balloon flight in Texas, in April 1965. The flux value derived was 110 ± 8 particles/m 2/sec. ster, substantially in excess ofthat expected on the basis of data obtained in 1954-6, at the time of the previous minimum in solar activity. A re-examination of published records of older flights shows that the geomagnetic cut-off values assumed were in error. Discussions of solar modulation effects in the high energy region will require modification.