Inorganic Lead can cause a toxic effect on Central Nervous System, Peripheral Nervous System and Autonomic Nervous System (ANS). A damage of the ANS can determine an heart rate variability (HRV) reduction. In this study 43 battery workers exposed to inorganic lead with mean PbB = 31.63 microg/dl (DS 14.77 microg/dl) and 35 not exposed subjects underwent to an evaluation of heart rate variability by specific tests. Heart rate variability in the exposed group was, for some tests (lying to standing, lying to standing-standing to lying) reduced compared with not exposed subjects and for other tests (Valsalva manouvre, lying to standing-standing to lying) correlated with PbB and Zinc Protoporphyrin (ZPP), but not with BMI, age and smoking habits. This study, like others conducted on similar populations, suggest an effect of occupational inorganic lead exposure on Autonomic Nervous System and heart rate variability