Introduction: The literature investigated the effects of chronic classical music auditory stimulation on the cardiovascular system. However, it lacks in the literature the acute effects of different styles of music on cardiac autonomic regulation. We aimed to evaluate the acute effects of classical and heavy metal music on heart rate variability (HRV) in women. Method: The study was performed in 21 healthy women between 18 and 30 years old. All subjects signed a consent letter and all procedures were approved by the Ethic Committee in Research of UNESP. We excluded persons with previous experience with music instrument and those who had affinity with the song styles. We analyzed HRV in the time (SDNN, RMSSD, NN50 and pNN50) and frequency (LF, HF and LF/HF ratio) domains. HRV was recorded at rest for ten minutes. Subsequently they were exposed to classical or heavy metal music for five minutes through an earphone. After the first music exposure they remained at rest for more five minutes and them they were exposed again to classical or heavy metal music. The sequence of songs was randomized for each individual. Results: In relation to the time-domain index, we did not observe significant changes during exposure to classical and heavy metal musical auditory stimulation. The SDNN index tended to be reduced during heavy metal music style exposure (39.1+10 ms) compared to the control condition (47.3+19 ms), however, there was no statistical significance (p=0.12). The RMSSD (control: 40.8+23 ms vs. classical music: 38+19 ms vs. heavy metal music: 39.1+20 ms; p=0.8) and pNN50 (control: 22.5+22 vs. classical music: 20.6+20 vs. heavy metal music: 22.5+23; p=0.9) indices were not changed during musical auditory stimulation with the both styles. The LF index was significantly reduced during heavy metal music auditory stimulation compared to the control condition (control: 685.7+571 ms2 vs. classical music: 595.7+837ms2 vs. heavy metal music: 328.8+143 ms2; p=0.025). On the other hand, there was no significant changes with respect to the HF (control: 1059+1191ms2 vs. classical music: 638.2+639ms2 vs. heavy metal music: 695.3+678ms2;p=0.1) and LF/HF (control: 2+2 vs. classical music: 1.4+1 vs. heavy metal music: 2+3; p=0.7) indices. Conclusion: Acute exposure to heavy metal musical auditory stimulation reduces the sympathetic activity on the heart.