This review evaluates the potential benefits as well as adverse effects from adjunctive therapy with systemic steroids in patients with pneumonia: either mild-to-moderate or severe, community-acquired or hospital-acquired, of bacterial or of viral origin (in particular H1N1 viral infection). Recent findings Steroids potentially modulate the marked and persistent activation of the immune system in pneumonia. However, several recent randomized controlled trials and large prospective observational studies have repeatedly shown that steroids had no impact on survival, the clinical event of interest, but in severe pneumonia some studies pointed to potential harmful effect. In addition, adverse effects, namely hyperglycemia, superinfections, as well as increased length-of-stay, were frequent findings in the steroid-treated patients. Summary According to the current evidence, there are no data to support the well tolerated use of systemic steroids as a standard of care in pneumonia, neither in mild-to-moderate and severe, nor in bacterial and viral infection. Clinical and basic research should work together to improve trial designs to identify reliable surrogate markers of outcome, in particular of mortality. This may improve the patient selection and facilitate the identification of subgroups that can benefit from adjunctive steroid therapy.