Abstract A geriatric, 16‐year‐9‐month‐old, male snow leopard ( Panthera uncia ) under human care was necropsied after euthanasia over concerns for worsening chronic kidney disease and bilateral blindness. Gross and histological examinations revealed necrotising frontal sinusitis and osteomyelitis with mixed‐cellular rhinotracheitis, affecting the right frontal sinus, right nasal cavity and trachea, respectively, with intralesional and cilia‐associated Gram‐negative bacilli detected. Microbiological cultures were inconclusive, although Bordetella bronchiseptica and feline herpesvirus 1 were positive on PCR analysis. Immunohistochemistry, however, refuted active feline herpesvirus 1 involvement. Marked, chronic, bilateral, renal degeneration and fibrosis (chronic kidney disease), mild hepatic cirrhosis, bilateral chronic degenerative stifle joint disease and testicular intratubular seminoma were also detected on postmortem examination. No gross ocular or optic nerve lesions were identified; however, histology indicated bilateral diffuse outer retinal atrophy and retinal detachment, supportive of clinical blindness at time of death. This case represents the first report of chronic rhinosinusitis and osteomyelitis in a snow leopard.