The aim of this study was to determine the prevalence of Human T cell Leukaemia Virus Type 1 (HTLV1) in a representative population sample, in neurological and non-neurological patients hospitalised in the Lomé teaching hospital in order to study the clinical manifestations of this retrovirus. There was no statistical difference among the three groups concerning the prevalence of HTLV1 respectively (1.2%: 21/1717, 1.8%: 15/828 and 1.6%: 4/244). Spastic paraparesis was the only disease significantly linked to HTLV1 (15.5%: 9/58).