The symptoms of chikungunya virus (CHIKV) infection include fever, headache, muscle aches, skin rash, and polyarthralgia, characterized by intense pain, edema, and temporary functional impairment. This is the first report of encephalitis caused by CHIKV infection associated with an atypical presentation of syndrome of inappropriate antidiuretic hormone secretion, evolving to cognitive impairment and apraxia of speech.