Jamaican Neuropathy of the ataxic type (tropical ataxic neuropathy [TAN] and spastic type (tropical spastic paraparesis [TSP]) have been recognized for over a century in Jamaica. The recent association of TSP with HTLV-I (TSP/HAM) is now well established. We now present evidence for a possible association between a TAN-like illness with HTLV-II in four females aged 34-49. All presented with ataxic gait and all four have prominent mental changes. Three of the four also have minor motor deficits with urinary frequency and two have nocturnal leg cramps. All have serum antibody and all had PCR evidence of HTLV-II infection. Antibody to HTLV-II is present in CSF from two subjects. The distinctive picture of prominent ataxia and altered mental status in these subjects contrasts with a predominantly myelopathic picture seen in TSP/HAM.