A vibrating-wire viscometer of very high precision was used to measure the viscosity of gaseous ethane. The experimental data were taken at subcritical temperatures of (290 and 300) K up to 88 % of the saturated vapor pressure and at supercritical temperatures of (310, 320, 340, 370, 400, and 430) K at pressures up to a maximum of 30 MPa. The measuring values were evaluated using an equation of state by Bucker and Wagner. The reproducibility is +/- (0.05 to 0.1) %, whereas the total uncertainty is estimated to be +/- (0.25 to 0.4) % with an increase of (1 to 2) % close to the critical point. The viscosity values of the isotherms were correlated as a function of reduced density using a power series expansion. A comparison with correlations from the literature shows deviations up to about 5 % in the near critical region and up to 2 % at higher densities and temperatures. On the basis of a comparison with direct experimental data from the literature, it is concluded that the new values are the most reliable for the improvement of the viscosity surface correlation of ethane.