Faraday rotation (FR) measurements using linearly polarized radio signals from the two Helios spacecraft were carried out during the period from 1975 to 1984. This paper presents the results of a spectral analysis of the Helios S-band FR fluctuations observed at heliocentric distances from Fig. 3 to16 R⊙during the superior conjunctions 1979–1984. The mean intensity of the FR fluctuations usually does not exceed the noise level for solar offsets greater than≃15 R⊙.The rms FR fluctuation amplitude increases rapidly as the radio ray path approaches the Sun. Good representations of the radial variation were obtained with a two-term empirical formula. The equivalent two-dimensional FR fluctuation spectra are well modeled by a single power-law over the frequency range from 1 to 50 mHz. There is a tendency for an increase of the spectral index from 1.2 at solar offset distancesR>10 R⊙to 1.6 atR<6 R⊙,corresponding to a range for the three-dimensional spectral indexp=2.2–2.6. FR fluctuations thus display a somewhat lower spectral index compared with phase and amplitude fluctuations. Finally, a quasiperiodic component, believed to be associated with Alfve´n waves, was discovered in selected fluctuation spectra observed simultaneously at two ground stations. Characteristic periods and bulk velocities of this component were240±30 secand300±60 km/s,respectively. ©1996 American Institute of Physics.