INTRODUCTION: Laryngeal transplantation remains an increasingly viable option for patients with irreversible disease or damage to the larynx. Successful organ transplantation relies on minimising surgical, ischaemic and immunological insults. The inherent immunogenicity of an organ is dependent on the amount of immunologically active cells within it. The presence of immunologically active cells within non-transplanted NIH-minipigs was investigated and an in vivo laryngeal transplant model was developed. MATERIALS AND METHODS: Quantitative, multiple-colour immunofluorescence using pig-specific monoclonal antibodies was used to assess the normal immunological architecture and the short-term immunological changes associated with 3 h of cold ischaemia and 8 h of reperfusion in an MHC-matched animal model. RESULTS AND CONCLUSIONS: There is a complex immunological architecture within the non-transplanted, healthy pig larynx. In addition, an in vivo laryngeal transplant model was developed that allowed successful perfusion for 8 h post transplantation. There were significant changes in cell numbers within different anatomical subsites of the larynx. However, the biological significance remains debatable in view of the large range of cell numbers both within and between individual animals