We explored the effects of daily subcutaneous rotenone injections (1.5–2.5 mg/kg). Ultrastructural changes were observed in the substantia nigra at all doses. A dose-dependent increase in α-synuclein was also observed. 2 mg/kg/day rotenone reproduces behavior and neuropathology of parkinsonism. The low mortality rate at 2 mg/kg/day allows for practical application.