Acute Myeloid Leukemia (AML) is an aggressive and rare cancer of myeloid cells (a white blood cell responsible for fighting infections). This study will assess how safe and effective oral venetoclax is in participants with AML . Adverse events and change in disease activity will be monitored under routine clinical practice. Venetoclax is an approved drug for treatment of Acute Myeloid Leukemia (AML). Around 600 participants of age 19 years and above will be enrolled in the study in multiple medical institutions across South Korea. Participants will receive oral venetoclax tablets as prescribed by their physician in the routine clinical practice. Participants will be observed for 7 cycles ( each cycle is 28 days). There may be higher treatment burden for participants in this trial compared to their standard of care. Participants will attend regular visits during the study at a hospital or clinic. The effect of the treatment will be checked by medical assessments, blood tests, checking for side effects and completing questionnaires.