Aging is associated with autonomic activity modifications. Heart period (HP) variability-(HPV) analysis reveals a progressive reduction of parasympathetic modulation and increase of sympathetic modulation during senescence. Additionally, the QT interval variability (QTV), defined as the time between Q-wave onset and T-wave end, has been employed to assess sympathetic modulation directed to the ventricles. However, few studies have addressed its relationship with age. This study evaluates the age-related changes in QTV and compares them with the those in HPV. We studied 111 male subjects divided into five age groups: 20-29, 30-39, 40-49, 50-59, and 60-69. The electrocardiogram was acquired at rest in supine position (REST) and during active standing (STAND). Sequences of 256 consecutive HP and QT measures were considered. Time domain indices, namely HP and QT means (μHP and μQT) and variances (σ2HP and σ2QT), and frequency domain indices derived in the high frequency (HF, 0.15-0.5 Hz) and low frequency (LF, 0.04-0.15 Hz) bands of HPV and QTV, namely the power HFaHP of the HP series and the power LFaQT of the QT series were calculated. Lower values of σ2HP and HFaHP at REST were observed in the last two decades compared to the youngest one. STAND reduced further these values. At REST higher values of σ²QT and LFaQT were found especially in the 50–59 and 60–69 age groups compared to the youngest one. STAND increased further these values. Our findings showed that both HPV and QTV are age-dependent, with the most significant QTV alterations occurring in the late bins of age. Spectral analyses of HRV and QTV suggest a reduced vagal and increased sympathetic modulations with age.