Pseudotumor cerebri is a condition characterized by increased intracranial pressure with normal cerebrospinal fluid composition. It is usually associated with many medical conditions and drugs. It has been reported that all-trans-retinoic acid can induce pseudotumor cerebri. The authors report a 35-year-old patient diagnosed with acute promyelocytic leukemia who developed pseudotumor cerebri after receiving all-trans-retinoic acid. The patient was treated with 60 mg/day of all-trans-retinoic acid. Two weeks later, she had severe headache and blurred vision. The neurological examination revealed papilledema and decreased visual acuity. Other physical examinations were unremarkable. Brain CT was normal. Additionally, lumbar puncture was performed and the CSF finding was normal except for high CSF pressure. According to modified Dandy criteria, the diagnosis was pseudotumor cerebri. The patient's symptoms disappeared after all-trans-retinoic acid was discontinued. To our knowledge, this is the first case report in Thailand.