Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) (301092/2018-4), Fundação de Amparo à Pesquisa do Estado da Bahia (Fapesb)(CNV0072/2013) and Fundação Nacional para o Desenvolvimento do Ensino Superior (Funadesp).The prevalence of keratoconjunctivitis sicca (KCS) associated with Human T-Cell Lymphotropic Virus Type 1 (HTLV-1) (HTLV-1/KCS) has been estimated at around 37%, but its clinical manifestations are poorly described. Purpose: To determine the prevalence and associated factors of HTLV-1/KCS in a large cohortof HTLV-1-infected individuals living in Salvador, Brazil.Methods: A cross-sectional study was conducted between June 2004 and September 2017 atthe Integrative and Multidisciplinary Center for HTLV in Salvador, Bahia-Brazil. Data from758 HTLV-1-infected patients was collected. A complete ophthalmologic examination wasperformed in both eyes. Lacrimal function was evaluated by breakup time, Rose Bengaland Schirmer I Tests. KCS diagnosis was considered in the presence of at least two out ofthree positive tests. HTLV-1 proviral load Crude and Adjusted Prevalence Rates (PR) with95% Confidence Intervals (95% CI) were estimated using multivariate Poisson Regressionwith robust error variance.Results: The overall prevalence of KCS was 31.7%, with higher rates observed in HTLV-1-associated myelopathy/tropical spastic paraparesis patients (crude PR: 1.84; CI95%:1.50–2.26) even after adjusting for age, sex, time of HTLV-1 diagnosis and schooling (adjustedPR: 1.63; CI95%: 1.31–2.02). Proviral load, low corrected visual acuity, burning and/or pain anditching were all significantly higher in patients with KCS.