Natural paratuberculosis infection of rabbits (Oryctolagus cuniculus) was recently diagnosed in Scotland, and an investigation into the pathology of the disease in wild rabbits is reported in this paper. Evidence of Mycobacterium avium subsp. paratuberculosis (M.a. paratuberculosis) infection was detected in 22% of 110 rabbits: the organism was cultured from 17 of 110 rabbits, Land histopathological lesions consistent with many. paratuberculosis infection were noted in 18 of 98 rabbits examined. No macroscopical lesions suggestive of M.a. paratuberculosis infection were observed. The histopathological le,ions were either severe or mild. Severe lesions consisted of extensive macrophage granulomata and numerous giant cells, with many intracellular acid-fast bacteria in the small intestine. For the examination formalin-fixed, paraffin wax-embedded tissues, neither immunohistochemistry nor the polymerase chain reaction was as sensitive a method of diagnosis as histopathology.