Chronically heightened physiological reactivity to or delayed recovery from stress may contribute to cardiovascular (CV) risk and mortality. Long‐term stability of physiological stress responses has received little attention. Our objectives were to evaluate the 3‐year stability of reactivity and recovery change scores across CV and autonomic parameters and assess whether sex and age moderate stability. A total of 134 healthy participants underwent two laboratory stress protocols, including four 5‐min interpersonal stressors, each followed by a 5‐min recovery period. Heart rate (HR), blood pressure (BP), and HR variability (high frequency, low frequency, very low frequency [VLF]) were obtained. Spearman rank correlations and linear regressions were performed. Significant correlations emerged for all physiological measures except diastolic BP and VLF recovery. No significant sex or age differences were found. Stress responses represent stable individual traits little affected by sex or age.