OBJECTIVE This study aimed at analysing quality of life (QOL) indicators of patients with sickle cell disease (SCD) in treatment, investigating the epidemiological, socioeconomic and care situation provided to patients with SCD in the State of Maranhão, one of the poorest states of Brazil. METHODS: A cross-sectional study was carried out from March 2018 to February 2019, with the application of a generic quality of life questionnaire, SF-36, to patients attending a referral center for treatment of hemoglobinopathies in the State of Maranhão. 113 patients with SCD were interviewed and sociodemographic data, disease characteristics and laboratory tests (hemogram, foetal haemoglobin, DHL and reticulocytes) were collected. The SF-36 questionnaire was then applied. RESULTS: Most of the 113 patients were female, with a mean age of 26 years, declaring themselves to be of brown colour and living in the interior of the State. Most were unemployed, having low income and low schooling. About 92% were of the SS subtype, the most serious subtype. The percentage of neonatal diagnosis was only 27.4%. Regarding the SF-36 questionnaires, quality of life was classified as poor in relation to the physical component and good in the mental component. The use of hydroxyurea, the only medication approved in Brazil for the control and prevention of pain, promoted an improvement in the physical appearance of patients with SCD, howbeit, with no relation to the prevalence of clinical complications. CONCLUSIONS: The use of the SF-36 generic questionnaire showed impairment in the quality of life in the physical domains of patients with SCD, worsening in cases in which there was delayed diagnosis; in those individuals who claimed to have suffered prejudice; and in patients hospitalised for pain attacks. No deterioration of the mental components was observed. This scenario implies a need for government action sensitive to this public health problem.