A case of 33-year-old female presented to the emergency room with recurrent migraine-like headaches accompanied by expressive dysphasia and right-sided weakness. Her laboratory workup, brain computed tomography (CT) and magnetic resonance imaging (MRI), and vascular imaging workup were unremarkable. However, cerebrospinal fluid (CSF) analysis revealed pleocytosis of 96 cells per microliter with predominated lymphocytes (97%). Xanthochromia testing, microscopy, and culture were negative. Surprisingly, all the symptoms were reversible within 12 hours, including headache and speech. Accordingly, a diagnosis of headache with neurological deficits and CSF lymphocytosis (HaNDL syndrome) was established. Managing HaNDL syndrome requires an interprofessional team approach. Acute and severe presentation with headache and focal neurologic deficit generally requires the patient to go through a series of investigations to reach this diagnosis. The investigations should be able to exclude more severe differential diagnoses, such as infectious, inflammatory, and neoplastic causes, before diagnosing HaNDL. Increased awareness and early detection of HaNDL can prevent unnecessarily prolonged courses of antimicrobial therapy and repeated use of invasive and expensive laboratory and imaging investigations such as cerebral angiography.