Central nerve system toxicity of fluoroquinolones is well known but nearly always benign. Old age, concomittant central nerve system disease, drug interactions and/ or partial or total loss of renal function are the major risk factors. Although, in literature there is very limited number of severe central nerve system toxicity cases related to fluoroqinolones, prompt realization is vital as the only therapy is discontinuation of the drug. In this article, two cases of acute central nerve system toxicity of ofloxacin with an unexpected severity are described.