A 42-year-old man presented to us with buttock pain of 1 week duration. Two days prior to admission, he developed high grade fever and back pain followed the next day by weakness of the right leg and intense twitching of the right thigh. He had grade 0/5 power in the right leg, 4/5 power in the left leg with absent deep tendon reflexes bilaterally and a normal sensory exam. Fasciculations were noticed over both thighs. An MRI spine with contrast was normal. Routine blood investigations were normal. CSF showed 135 cells with 93% lymphocytes and 7% polymorphs and normal sugar and protein. PCR for bacteria, including Mycobacterium tuberculosis, Streptococcus pneumonia, Neisseria meningitidis and HSV, CMV and varicella zoster virus were negative. He was treated for presumptive viral myelitis with acyclovir, ceftazidime and vancomycin for 10 days. Three serum samples collected within 2 weeks after the onset of central nervous system (CNS) symptoms were positive for both JEV and WNV IgM antibodies by IgM capture ELISA (JEV IgM ELISA, NIV Pune and WNV IgM ELISA, InBiosinc., USA). However, the serum samples on microneutralization assay showed significantly high titre of neutralizing antibodies to WNV (titre: 320) and undetectable neutralizing antibodies to JEV (titer <10) confirming the WNV etiology. His fever subsided, but he had residual flaccid paralysis of the right leg, proximal > distal at follow up 1 month later.