Background: The term idiopathic cytopenia of undetermined significance (ICUS) is used when the probable cause of pancytopenia is not clear and it sometimes has a fatal outcome. We report this case to highlight the role of high doses of steroid in the treatment of ICUS which altered the course of disease in the patient and rendered it non-fatal. Case Report: A 28-year-old female presented with shortness of breath, pallor, icterus, ecchymosis patches, Glasgow coma scale of 8/15, shock and respiratory failure. Investigations showed pancytopenia, deranged liver function test and coagulopathy. Despite being on standard treatment protocol for pancytopenia she remained in shock and had epistaxis following which a trial of high dose methylprednisolone was given and substituted with tapering dose of oral prednisone. The patient improved after this and is under 6 monthly follow-up. Conclusion: All cases of pancytopenia should be investigated thoroughly and an entity called idiopathic cytopenia of undetermined significance (ICUS) should be considered if no possible causes can be found. We share our experience of instituting steroids in a case of life threatening ICUS which benefitted the patient although the cause and mechanism were unknown.