Cardiovascular autonomic reflex tests based on heart rate variability (HRV) have proven useful for noninvasive detection of autonomic nervous system (ANS) regulation failure in numerous pathological conditions. Although previous studies have suggested that exposure to toxic metals might alter HRV, there were a number of potential limitations in those studies, including the determination of HRV in adults occupationally exposed to heavy metals. The aim of this study was to investigate the relation between lead and HRV in children using cardiovascular reflex tests. An assessment of cardiac autonomic regulation in children of both genders, aged 10 to 16 years (n=57), who had never been occupationally exposed to lead (Crimea, Ukraine) was carried out using the HRV markers and hair lead concentration determined by X-ray spectophotometry (ElvaX-Med). Five-minute HRV recordings by three-lead electrocardiography (Cardio, Ukraine) were obtained in supine position and during cardiovascular reflex tests (active tilt test, after exercises, during deep breathing, oculocardiac reflex and the psychometric strain test) and standard time and frequency domain HRV parameters were examined. Time-domain indexes included: normal-to-normal intervals (RRNN) between adjacent QRS complexes, the standard deviation of the NN intervals (SDNN), square root of the mean sum of squares of the differences between adjacent NN intervals (rMSSD), and proportion of pairs of adjacent NN intervals differing by more than 50 ms (pNN50). The frequency domain indexes were: high (HF), HF in normalized units (HFn), low (LF), LF in normalized units (LFn), very low (VLF), total power (TP), and the LF/HF ratio. The results showed no statistically significant correlations between Pb and HRV indices recorded at rest. Statistically significant positive Spearman correlations were found only for lead and SDNN, VLF in oculocardiac reflex (0.27<r<0.40; p<0.05); lead and SDNN, TP, LF, HF during deep breathing (0.28<r<0.31; p<0.05); lead and rMSSD, pNN50, HF (0.26<r<0.29; p<0.05) during active orthostatic test. Most of the correlations were observed between Pb and HRV parameters recorded after exercises: positive with RRNN, SDNN, rMSSD, pNN50, TP, LF, HF, VLF, HFn and negative with LF/HF and LFn (0.27<r<0.42; p<0.05). Revealed correlations suggest an increased parasympathetic activity in participants with higher lead concentrations during various cardiovascular tests, indicating that lead affects the vagal nerve more than other cardiac nerves. Pb levels were also associated significantly with heart rate during oculocardiac, orthostatic test and after exercises, suggesting negative chronotropic effect of lead (-0.29<r<-0.36; p<0.05). These findings suggest that recording HRV during simple cardiovascular tests may be more sensitive than recordings during supine rest in low-level lead exposure in children.