Oxime-type AChE reactivators pralidoxime, obidoxime, trimedoxime, methoxime and HI-6 were tested for their potential to affect the activity of monoamine oxidase of type A (MAO-A) and type B (MAO-B) in crude mitochondrial fraction of pig brains. The in vitro potency of oximes to change MAO activity seems to be weak; hence, all oximes tested can be taken as relatively safe compounds regarding to drug-induced changes in MAO activity and related changes in monoaminergic neurotransmission.