Novel perfluoroalkyl-substituted mono-, di- and poly-amide compounds which are reaction products of a mono-, di- or polyamine of 60 to 2000 molecular weight with a perfluoroalkyl substituted unsaturated acid or its corresponding lower alkyl ester and optionally a non-fluorinated amino-reactive compound such as an acid, ester, anhydride, epichlorohydrin, isocyanate or urea, are useful as internally or externally applied paper sizes to impart oil and grease resistance to paper, and as oil proofing coatings on textiles, wood, masonry and the like, or as high-performance surface active agents.