The inﬂuence of tin doping on the electrical, optical, structural and morphological properties of indium oxide ﬁlms produced by radio-frequency plasma enhanced reactive thermal evaporation is studied, as transport properties are expected to improve with doping. Undoped and tin doped indium oxide thin ﬁlms are deposited at room temperature using both pure In rods and (95-80) % In:(5-20) % Sn alloys as evaporation sources and 19.5 mW/cm2 and 58.6 mW/cm2 as rf-power densities. The two most important macroscopic properties - visible transparency and electrical resistivity - are relatively independent of tin content (0-20%). Visible transmittance of about 75% and electrical resistivity around 5×10-4 Ω·cm can be observed in the ﬁlms. The structural features are similarfor all samples. Nevertheless, the surface morphology characterization shows that the homogeneity of the ﬁlms varies according to the tin content. Moreover this variation is a balance between the rf-power and the tin content in the alloy: i) ﬁlms with small and compact grains are produced at 58.6 mW/cm2 from a 5% Sn alloy or at19.5 mW/cm2 from a 15% Sn alloy and consequently, smooth surfaces with reduced roughness and similar grain size and shape are obtained; ii) ﬁlms showing the presence of aggregates randomly distributed above a tissue formed of thinner grains and higher roughness are produced at the other deposition conditions.