Amoebic Gill Disease (AGD), caused by the ectoparasite Paramoeba perurans (P. perurans) is characterised by hyperplasia of the gill epithelium and lamellar fusion and has become recognised as one of the most significant health threats in salmon farming . In this study, the gill and serum proteomes of Atlantic salmon inoculated with P. perurans, across multiple timepoints post-challenge, were analysed. The expression of proteins with established roles in innate immunity, across various timepoints, was compared with expression in naïve Atlantic salmon to elucidate the host response to gill colonisation.