We report a case of rhinocerebral mucormycosis in a 31 year old immunocompetent female presenting initially like acute rhinosinusitis with nasal stuffiness, severe headache, vomiting who soon developed isolated right lateral rectus palsy. Computed tomography(CT) scan of the Post-Nasal Spaces(PNS) showed an ill defined expansile heterogenous density mass in the sphenoid with extension into the ethmoids, nasal cavity, optic canal, superior orbital fissure, clivus and right temporal lobe with signal void in Magnetic Resonance Imaging(MRI). The debris and polypoid mucosa obtained on nasal endoscopy revealed mucormycosis on histopathologic examination. The patient was managed with urgent surgical debridement and medical managemen.