The aim of this study was to assess and to compare heart rate variability (HRV) after resistance exercise (RE) in treated hypertensive and normotensive subjects. Nine hypertensive men [HT: 58.0 +/- 7.7 years, systolic blood pressure (SBP) = 133.6 +/- 6.5 mmHg, diastolic blood pressure (DBP) = 87.3 +/- 8.1 mmHg; under antihypertensive treatment] and 11 normotensive men (NT: 57.1 +/- 6.0 years, SBP = 127 +/- 8.5 mmHg, DBP = 82.7 +/- 5.5 mmHg) performed a single session of RE (2 sets of 15-20 repetitions, 50% of 1 RM, 120 s interval between sets/exercise) for the following exercises: leg extension, leg press, leg curl, bench press, seated row, triceps push-down, seated calf flexion, seated arm curl. HRV was assessed at resting and during 10 min of recovery period by calculating time (SDNN, RMSSD, pNN50) and frequency domain (LF, HF, LF/HF) indices. Mean values of HRV indices were reduced in the post-exercise period compared to the resting period (HT: lnHF: 4.7 +/- 1.4 vs. 2.4 +/- 1.2 ms(2); NT: lnHF: 4.8 +/- 1.5 vs. 2.2 +/- 1.1 ms(2), p < 0.01). However, there was no group vs. time interaction in this response (p = 0.8). The results indicate that HRV is equally suppressed after RE in normotensive and hypertensive individuals. These findings suggest that a single session of RE does not bring additional cardiac autonomic stress to treated hypertensive subjects.