PROBLEM TO BE SOLVED: To provide a radiation-sensitive resin composition excellent in all of line edge roughness, pattern features, followability for an immersion liquid and dry etching durability, and to provide a resist film and a pattern forming method using the composition.SOLUTION: The radiation-sensitive resin composition contains: (A) a resin having a repeating unit expressed by general formula (I-1) or (I-2); and (C) a compound, which has a molar absorption coefficient ε, at a wavelength of 193 nm measured in an acetonitrile solvent, of a relative ratio of 0.8 or less with respect to triphenylsulfonium nonafluorobutane sulfonate and which generates an acid by irradiation with radiation. In general formulae (I-1) and (I-2), ARand ARrepresent an aromatic group; Rrepresents an alkyl group, a cycloalkyl group or an aryl group; Aand Aeach independently represent a hydrogen atom, an alkyl group, a halogen atom, a cyano group or an alkyloxycarbonyl group; and Z represents a linking group to form a ring together with C-AR.