Objectives. To assess the neurotoxic effect of the aqueous extract of boldo (Peumus boldus) in an experimental model. Materials and methods. 20 male Holtzman rats of 250 ± 15 g were randomized into four groups: the negative control received saline solution (SS) orally (PO), the positive control received 6-hydroxydopamine intracranially (IC) and SS by PO. Experimental group 1 received aqueous extract of boldo (AEB) by PO, and experimental group 2 received 6-hydroxydopamine intracranially and AEB by PO. The experiment lasted 21 days. A neurological assessment was performed which had three components: a) clinical, evaluated with the rotarod test, b) biochemical, by measuring serum levels of uric acid, and c) histopathology, by immunohistochemistry for substantia nigra dopaminergic neurons. The Kruskal Wallis test and the Dunn test were used to assess differences between groups. Results. A significant decrease was found in the latency time of the rotarod test between the negative and positive control group (p<0.01), negative control and experimental 1 (p=0.09), negative control and experimental 2 (p;0.01), positive control and experimental 1 (p=0.04), and experimental 1 and 2 (p=0.09). There was no significant intergroup difference in the identification of uric acid. There was a depletion of the total dopaminergic neurons in the neuronal count, without intergroup difference. Conclusions. A neurotoxic effect of aqueous extract of boldo was recognized at a clinical level in Holtzman male rats.