Aim:Lumbar disc herniation (LDH) affects many individuals and oxidative stress is associated with the degeneration of the disc and so with LDH. Paraoxonase 1 (PON1) has antioxidant properties, and its activity can differ depending on genetic variations and ethnic background. This study aimed to compare PON1 activity and phenotype distribution in LDH patients and healthy individuals. Material and Methods:This research included 40 LDH patients and 42 healthy individuals. Spectrophotometric assays were used to determine serum PON1 and arylesterase activities. The PON1 ratio, which represents the salt stimulated paraoxonase/arylesterase level, was found to have a trimodal distribution. This ratio was used to identify the different phenotypes; QQ, QR, and RR of each subject.Results:The LDH patients had lower PON1 activity than the healty individuals (p<0.05). LDH patients had a statistically significant QQ phenotype compared to healty group (p<0.05).Conclusion:We found that LDH patients had statistically lower PON1 activity, and this investigation suggests that the low PON1 activity and PON1 QQ phenotype may be a risk factor for LDH occurence.