Objective: The diagnostic workup of uveitis is a challenge due to the wide range of diagnoses and the lack of a well-codified diagnostic procedure. We aimed to evaluate the relevance of diagnostic investigations for the etiological diagnosis of uveitis. Methods: Retrospective cohort study of patients referred for etiological diagnosis of uveitis. Uveitis related to ophthalmological diseases or occurring during the course of previously diagnosed diseases were not included. Results: Three hundred patients were included. Chest CT-scan was suggestive of sarcoidosis in 83 (29%). Features associated with abnormal CT-scan were: snowballs and/or peripheral multifocal choroiditis (PMC) upon ocular examination (P = 0.004), blood lymphopenia (P1.5 ULN (P=0.0003). Bronchoscopy showed granuloma in 18 (11%) while alveolar lymphocytosis suggestive of sarcoidosis was reported in 45 (27%). Presence of granulomaon bronchial biopsies was always associated with chest CT-scan abnormalities, whereas 31% of patients with alveolar lymphocytosis had normal CT-scans. Features associated with contributive bronchoscopy were: snowballs and/or PMC (P = 0.003), ACE N 1.5 ULN (P = 0.007), abnormal chest-CT scan (P = 0.0001). Salivary gland biopsy revealed granuloma in 12 patients (5%). Cerebral MRI was abnormal in 15 patients (9%) who mostly presented with snowballs and/or retinal vasculitis. Finally, the main causes of uveitis were latent tuberculosis (25%) and sarcoidosis (22%), but 34% remained of undetermined origin. Uveitis relapses were observed in 31% and did not differ between patients with an identified diagnosis and those with idiopathic uveitis. Conclusion: Identification of factors associated with abnormal investigations might improve the optimal diagnostic workup adapted to each patient. (C) 2017 Published by Elsevier B.V.