In the past decade, a new form of therapy based on biological rather than pharmacological intervention has been developed. The term 'cell therapy', as applied to this new therapeutic tool, means the administration of living, non-germline somatic cells to humans for diagnostic or therapeutic purposes. Cell therapy products (CTPs) are generated by ex vivo processes, which comprise cell harvesting from patients or healthy donors, in vitro manipulation and administration of the manipulated cells to patients. The aim of ex vivo processes is to obtain cell subsets with defined functional properties that are capable of replacing or repairing damaged tissues or organs. Some examples of cell therapy are transplantation of expanded haematopoietic stem cells (HSCs), adoptive immunotherapy and dendritic cell vaccination to augment or restore the immune response for the treatment of malignant or infectious diseases. The types of cells most frequently used for cell therapy include haematopoietic pluripotent progenitor and stem cells from the bone marrow and peripheral blood, T-cell clones and dendritic cells. Although CTPs should be produced according to good manufacturing practice, they differ from traditional pharmaceutical products with regard to quality control and safety aspects. These differences prompted the development of a number of documents issued by regulatory bodies, which specifically address CTPs. This review discusses several issues related to the design, construction and validation of a hospital-based facility for the production of CTPs, the implementation of cell-manipulation processes and quality control of the final products.