A prospective study was carried out on 48 patients with HTLV I associated myelopathy/tropical spastic paraparesis (HAM/TSP) to assess the association between this entity and Sjögren's syndrome. Fourteen patients (29.1%) had chronic dacryosialadenitis confirmed by a positive Schirmer's test and salivary gland biopsy. None of these patients had evidence of collagen disease and tests for Ro, La, and rheumatoid factor were negative except in one case. Therefore, the dacryosialadenitis could not be classified as either primary or secondary Sjögren's syndrome. Ten of the 14 patients (71.4%) had other systems (haematological, articular, dermatological, or respiratory) involved apart from the neurological and exocrine gland pathology. The findings suggest that the dacryosialadenitis associated with HTLV I is a disease of viral origin distinct from Sjögren's syndrome.