Purpose Ocular sarcoidosis is diagnosed based on suggestive intraocular findings and systemic investigations. In this study, we assessed the clinical usefulness of systemic parameters in the diagnosis of ocular sarcoidosis. Study design A retrospective study. Methods This study included 79 cases (19 men, 60 women) with ocular sarcoidosis who visited Hokkaido University Hospital from 2011 to 2015 and were followed up for more than one year. The control group was 91 cases of other uveitis (38 men, 53 women). All cases underwent blood examination for the measurement of angiotensin-converting enzyme (ACE), Krebs von den Lungen-6 (KL-6), soluble interleukin-2 receptor (sIL-2R), and calcium (Ca) levels. Bilateral hilar lymphadenopathy (BHL) was also examined by plain chest X-ray and contrasting chest computed tomography (CT). Results The sensitivity for sIL-2R (76.4%) was higher than for ACE (37.7%), KL-6 (26.3%), and Ca (11.8%), although all showed high specificity: ACE (97.5%), KL-6 (96.2%), sIL-2R (93.8%), and Ca (95.1%). From these results, the Youden index of sIL-2R (0.70) was higher than that of ACE (0.35), KL-6 (0.26), and Ca (0.07). Imaging tests revealed better detection of BHL by contrasting chest CT (82.7%) than by plain chest X-ray (29.5%). Conclusion The present findings indicate that the systemic parameters, particularly serum sIL-2R levels and BHL on contrasting chest CT, are useful biomarkers for the diagnosis of ocular sarcoidosis.