The objective of this work was to determine microscopic structural features of three methacrylate polymers with different numbers of diethylene glycol residues and zwitterionic pendant groups. X-ray diffraction, electron microscopy, and scanning probe microscopy techniques were employed. X-ray data led to the adoption of a model made up of molecular aggregates forming lamellar domains, establishing in this way ordered characteristics of these kinds of polymers. Scanning electron microscopy images provided evidence of the occurrence of a lamellar structure forming the morphology of the polymers. This was corroborated by atomic force microscopy experiments. Transmission electron microscopy revealed that the lamellar aggregates conformed into clusters immersed in a polymeric matrix. From phase-contrast images, information on the homogeneity of the composition at a molecular surface level was obtained. Then, the techniques provided evidence of the lamellar domain characteristics of the studied sulfobetaines. The crystallinity was a function of the number of ethoxy groups because as this number increased, the crystallinity became lower. (c) 2005 Wiley Periodicals, Inc.