A simple one-pot reaction that serves to functionalize graphite nanosheets (graphene) and single-walled carbon nanotubes (SWNTs) with perfluorinated alkyl groups is reported. Free radical addition of 1-iodo-1H,1H,2H, 2H-perfluorododecane to ortho-dichlorobenzene suspensions of the carbon nanomaterial is initiated by thermal decomposition of benzoyl peroxide. Similarly, UV photolysis of 1-iodo-perfluorodecane serves to functionalize the carbon materials. Perfluorododecyl-SWNTs, perfluorododecyl-graphene, and perfluorodecyl-graphene are characterized by infrared (IR) and Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and atomic force microscopy (AFM). The products show enhanced dispersability in CHCl3 as compared to unfunctionalized starting materials. The advantage of this one-pot functionalization procedure lies in the use of pristine graphite as starting material thereby avoiding the use of harsh oxidizing conditions.