This work presents the first results on the development and characterization of novel nanobiocomposite fibers prepared by electrospinning of zein/clay mixtures (from 99/1 to 75/25 wt/wt) from ethanol-based solutions. To do so, commercial ceramic materials of different nature, such as organomodified and unmodified mica, kaolinite, montmorillonite, and zeolite were employed and compared. A significant decrease in fiber diameter was observed as the clay fraction increased in the hybrid material. The highest clay contents also produced fibers but with extended beaded regions. All fillers nanodispersed well in the fibers at low loadings but unmodified mica particles were also seen excluded from the fibers, most likely due to excessive size. Surprisingly, the ceramic laminar structures, i.e. the phyllosilicates, were all seen to embed within the ultrathin fibers in what appears as an unreported rolled morphology due to the extensional forces generated by the electrospinning process. Electrospun nanobiocomposite fibers with optimal ceramic nanoparticle contents are currently investigated as an adequate procedure to prepare naturally occurring composite additives, coatings, and interlayers with enhanced performance in terms of mechanical, thermal, barrier, and control release properties for packaging, active packaging, biomedical, and pharmaceutical applications. (C) 2010 Wiley Periodicals, Inc. J Appl Polym Sci 118: 778-789, 2010