The prevalence of Parkinson's disease is increasing every year. This progressive disease is characterized by the loss of neurons in the substantia nigra due to the presence of alpha-synuclein aggregates. Keluwih leaves (Artocarpus camansi) are known to have activity in inhibiting acetylcholinesterase, as well as being an antioxidant and anti-inflammatory. The aim of this study was to evaluate the effect of ethanol extract of A. camansi leaves on the levels of alpha-synuclein in male and female adult zebrafish induced with rotenone. The zebrafish were induced with rotenone at a concentration of 5 µg/L for 28 days, along with the administration of 96% ethanol extract of A. camansi leaves at doses of 2.5, 5, 7.5, or 10 mg/L. The media was changed every 48 hours to maintain the concentration of rotenone and extract. After 28 days, alpha-synuclein levels were examined using immunohistochemistry. The administration of ethanol extract of A. camansi leaves can reduce the average levels of alpha-synuclein in male and female adult zebrafish, with the optimum dose being 2.5 mg/L. Therefore, it can be concluded that the administration of ethanol extract of A. camansi leaves can be used as an alternative treatment for Parkinson's disease.