The application of green chemistry principles in the processing of materials for advanced technologies is a steadily increasing field of research. In this work porous chitin-based materials were developed by combining the processing of chitin using ionic liquids (ILs) as a green solvent together with the use of supercritical fluid technology (SCF) as clean technology. Chitin was dissolved in 1-butyl-3-imidazolium acetate, followed by regeneration of the polymer in ethanol in specific moulds. The IL was removed using Soxhlet extraction and successive steps of extraction with SCF using carbon dioxide/ethanol ratios of 50/50 and 70/30. The developed porous chitin-based structures (ChIL) can be classified as mesoporous materials, with very low density and high porosity. The cytotoxicity of ChIL extracts was investigated using L929 fibroblast-like cells, and the results demonstrated that the produced materials have extremely low cytotoxicity levels. Therefore, the findings suggest that the porous chitin structures may be potential candidates for a number of biomedical applications, including tissue engineering.