Cat-scratch disease (CSD) was first described by Debré in 1950, yet the causative bacterial agent of CSD remained obscure until 1992, when Bartonella (formerly Rochalimaea) henselae was implicated in CSD by serological and microbiologic studies. Bartonella henselae had initially been linked to bacillary angiomatosis (BA), a vascular proliferative disease most commonly associated with long-standing human immunodeficiency virus infection or other significant immunosuppression. Bartonella henselae has also been associated with bacillary peliosis, relapsing bacteraemia and endocarditis in humans. Cats are healthy carriers of B. henselae, and can be bacteraemic for months or years. Cat-to-cat transmission of the organism by the cat flea, with no direct contact transmission, has been demonstrated. Two new Bartonella species have been identified in the cat reservoir, namely: B. clarridgeiae and B. koehlerae. The role of these species in the aetiology of CSD still needs to be confirmed by isolation or DNA identification from lesions in humans. The author discusses the present state of knowledge on the aetiology, clinical features and epidemiological characteristics of CSD/BA, in addition to diagnosis, treatment and prevention.