Background <p>Systemic corticosteroids, recommended for adult patients with coronavirus disease 2019 (COVID-19) who require supplemental oxygen, may carry an increased risk of reactivating latent infections such as hepatitis B virus (HBV) infection.</p> Methods <p>This retrospective observational cohort study of prospectively collected clinical data evaluated HBV screening frequency and examined the prevalence and reactivation of HBV among hospitalised adults treated with systemic corticosteroids for COVID-19 at a tertiary care hospital in Slovenia.</p> Results <p>Anti-HBc screening was conducted in 1,793/2,134 (84%) hospitalised patients receiving corticosteroids for COVID-19 (median age 70 years [IQR 59‒79 years]; 1,082 [60.3%] were male). Among the 1,793 screened patients, 157 (8.8%) were anti-HBc positive, and 5 (0.3%) of them also HBsAg positive. All five HBsAg-positive patients were aviremic. HBV infection was previously known in three of these patients (two on long-term tenofovir treatment) and identified <i>de novo</i> in two. Entecavir was initiated for one patient. Throughout the hospitalisations and 12-month follow-up periods, no cases of HBV viral rebound were observed in any of the HBsAg positive patients; one of the treated patients succumbed to COVID-19 pneumonia. No HBV reactivation or unexplained hepatopathy occurred in the 152 anti-HBc positive/HBsAg negative patients, none of whom were given antiviral prophylaxis.</p> Conclusions <p>Corticosteroids for COVID-19 did not appear to be a significant risk factor for HBV reactivation in cases of occult hepatitis B. Universal antiviral prophylaxis in HBsAg negative/anti HBc positive individuals may not be warranted with short courses of corticosteroids for COVID-19 in the absence of other risk factors for HBV reactivation.</p> Trial registration <p>Retrospectively registered with ClinicalTrials.gov, NCT07154212, September 2, 2025.</p>