We have previously demonstrated the protective function of hydrogen sulfide (H2S) against the neurotoxicity and oxidative stress of formaldehyde (FA). Paraoxonase-1 (PON-1) is a pivotal endogenous antioxidant. The aim of this present study is to investigate whether PON-1 mediates the protection of H2S against FA-induced neurotoxicity. In the present work, PC12 cells treated with FA were established to the model of FA-induced neurotoxicity. Treatment of PC12 cells with NaHS (a donor of H2S) not only upregulates the activity of PON-1，but also significantly restores FA-induced downregulation of PON-1 activity and expression. A selective inhibitor of PON-1, 2-hydroxyquinoline (2-HQ), markedly attenuated H2S-induced neuroprotection against FA-induced cytotoxicity, apoptosis, and accumulation of intracellular reactive oxygen species (ROS) in PC12 cells. Furthermore, 2-HQ blocks H2S to reverse FA-caused activation of caspase-3 and downregulation of bcl-2 expression in PC12 cells. These results indicate that H2S protects PC12 cells against FA-induced neurotoxicity in a PON-1-dependant manner. Our findings suggest a promising role of PON-1 as a novel therapeutic target for neuronal damage after FA exposure.