Essential thrombocythemia (ET), a subcategory of chronic myeloproliferative disorder, is characterized by absolute thrombocytosis due to excessive clonal proliferation of platelets, hyperaggregability of platelets, and increased incidence of thrombosis and hemorrhage. We consider a diagnosis of ET when an unexplained and persistent thrombocytosis is observed. It is difficult to consider ET first when we meet a patient with esophageal varix bleeding or unusual multiple thromboses like mesenteric vein, splenic vein, and portal vein. This article reports a patient who presented initially with esophageal varix bleeding and unusual multiple thromboses, thereafter, she was diagnosed with ET after testing positive for the Janus Tyrosine Kinase 2 (JAK2) V617F mutation. In conclusion, in patients with varix bleeding and unusual multiple thromboses, myeloproliferative disorders like essential thrombocythemia should be considered as a potential cause and testing for the JAK2 mutation is warranted.