Parkinson’s disease (PD) is a common movement disorder in the elderly. In the present study, we examined whether the combination of hyperbaric oxygen (HBO) and madopar therapy provided a neuroprotective effect on dopaminergic neurons in the substantia nigra using a rat model of PD. Rotational assessments revealed that both HBO and combination therapy significantly attenuated apomorphine-induced turning in PD rats. Our results indicated that the combination therapy increased glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities and reduced the malondialdehyde (MDA) content in the SN. Furthermore, the combination therapy resulted in significant protection against the loss of neurons, and specifically tyrosine hydroxylase (TH)-positive neurons, in the SN and also alleviated the production of glial fibrillary acidic protein (GFAP). The levels of Bcl-2 were increased and Bax were decreased following the HBO or combination therapy. In brief, the neuroprotective effect of combined therapy with HBO and madopar against 6-OHDA-induced PD rats may rely on its ability to reduce oxidative stress and protect against Bax/Bcl-2-mediated apoptosis.