Abstract Tropical spastic paraparesis (TSP), a chronic progressive myelopathy, occurs in Ethiopia in epidemic form as neurolathyrism, while the endemic form has remained obscure. We describe the clinical features of 22 patients with TSP and the results of screening for HTLV-1 in these patients, 26 patients with other neurological disorders, 14 patients with leukaemia and 66 blood donors. The major manifestations in the patients with TSP were weakness and spasticity of the lower limbs with upper motor neurone signs and minimal sensory loss and bladder dysfunction. Two patients with TSP (9%), 2 patients with other neurological disorders (7·7%) and one patient with leukaemia and deafness were seropositive for HTLV1. All the 66 blood donors were seronegative. Our results suggest that HTLV-1 may not play a major role in the pathogenesis of TSP in Ethiopia.