Cohort studies of large series of patients with sarcoidosis over a long period of time are scarce. The aim of this study is to report a 40-year clinical experience of a large series of patients at Bellvitge University Hospital, a tertiary university hospital in Barcelona, Spain. Diagnosis of sarcoidosis required histological confirmation except in certain specific situations. All patients underwent a prospective study protocol. Clinical assessment and follow-up of patients were performed by a multidisciplinary team.From 1976 to 2015, 640 patients were diagnosed with sarcoidosis, 438 of them (68.4%) were female (sex ratio F/M 2:1). The mean age at diagnosis was 43.3 ± 13.8 years (range, 14-86 years), and 613 patients (95.8%) were Caucasian. At diagnosis, 584 patients (91.2%) showed intrathoracic involvement at chest radiograph, and most of the patients had normal pulmonary function. Erythema nodosum (39.8%) and specific cutaneous lesions (20.8%) were the most frequent extrapulmonary manifestations, but there was a wide range of organ involvement. A total of 492 patients (76.8%) had positive histology. Follow-up was carried out in 587 patients (91.7%), over a mean of 112.4 ± 98.3 months (range, 6.4-475 months). Corticosteroid treatment was administered in 255 patients (43.4%), and steroid-sparing agents in 49 patients (7.7%). Outcomes were as follows: 111 patients (18.9%) showed active disease at the time of closing this study, 250 (42.6%) presented spontaneous remission, 61 (10.4%) had remission under treatment, and 165 (28.1%) evolved to chronic sarcoidosis; among them, 115 (19.6%) with mild disease and 50 (8.5%) with moderate to severe organ damage. A multivariate analysis showed that at diagnosis, age more than 40 years, the presence of pulmonary involvement on chest radiograph, splenic involvement, and the need of treatment, was associated with chronic sarcoidosis, whereas Löfgren syndrome and mediastinal lymphadenopathy on chest radiograph were indicators of good outcome.Sarcoidosis is a multisystem disease with protean clinical-radiographic manifestations. Although almost half of patients follow a spontaneous resolution or under treatment, a significant number of them may have several degrees of organ damage. This study emphasizes the value of a multidisciplinary approach and long-term follow-up by specialized teams in sarcoidosis.