OBJECTIVE : The composition and morphology of the internal and external surfaces of membranes are important for preventing migration of epithelial and connective cells, and allow the installation of osteogenic cells for bone growth. The objective of this study was to analyze the morphology and composition of three types of commercially available resorbable collagen membranes. METHODS Three types of collagen membranes, with different compositions and coming from different animals, were used: 1) Dental Surgidry F (bovine collagen type I); 2) Bio-Gide® (porcine collagen type I and III); and 3) OsseoGuard™ (bovine collagen type I). These membranes were analyzed using scanning electron microscopy and energy dispersive spectrometry. RESULTS The membranes showed distinct superficial architectures, porosities and chemical compositions. The membranes exhibited different surfaces and thicknesses, ranging from 0.32 mm to 0.75 mm. The chemical compositions exhibited a high percentage of niobium (Nb) in the Surgidry and OsseoGuard™ membranes; the Bio-Gide® membrane showed a greater proportion of calcium and aluminum relative to other elements. CONCLUSIONS Different types of resorbable collagen membranes exhibit different morphologies and chemical composition, which could lead to differences in the mode and time of resorption of the membranes used for guided tissue regeneration procedures.