Large fluxes of heavy ions have been reported upstream of Jupiter's bow shock as Voyager 1 approached the planet (Zwickl et al., 1981; Krimingis et al., 1985). Enhanced low-frequency magnetic wave activity was also observed during the particle events. The fluctuations are left-hand eliptically polarized in the plasma frame. The spectrum of these fluctuations contains a peak close to the Doppler-shifted resonance frequency of a sulfur or oxygen beam with streaming energy of approximately 30 keV. These fluctuations are also present in the spectrum of the magnitude of the field. We conclude that the observations result fron an instability driven by an energetic beam of either sulfur or oxygen. The wave observatons can be described by a heavy ion distribution with both a streaming anisotropy and a temperature anisotropy (T⊥/T∥ ≂ 2). This class of heavy ion streaming instabilities may also play a role in wave-particle interactions in the vicinity of comets.