Task of the HELIOS mission was the exploration of the inner heliosphere, inside the Earth's orbit to 0.3 AU. The Rome-GSFC magnetic field experiment has been a joint venture of an italian group (University of Rome and CNR/Istituto Fisica Spazio Interplanetario, Frascati) and an american group of NASA/Goddard Space Fligth Center, under the responsibility of F. Mariani and N.F.Ness, respectively. A description of the experiment can be found in the NASA-GSFC report X-692-75-112 (1975), by C. Scearce et al. The instrument is a dual configuration of two tri-axial fluxgate magnetometers operating at four different sensitivities (from 0.84 to 0.03 nT). The time resolution, depending the operation mode, telemetry format, and bit rate, for most cases varied from 0.07 to 1.5 seconds. The present data set contains six-second averages of the magnetic field elements in solar-ecliptic (SE) spacecraft-centered coordinates. Data are stored in files on a daily basis. File names are hNYYDDD.asc, with N the Helios number (1 or 2), YY the year (last two digits), and DDD the day of year (1 = January 1st). For instance, h276105.asc is the file with Helios 2 data for day 105, 1976.