OBJECTIVE: To evaluate the effect of low-dose monophasic oral contraceptives on female vocal quality. METHODS: Acoustic voice parameters of six women who use oral contraceptives and six women who do not were evaluated repeatedly during the menstrual cycle. Frequency and amplitude variations were measured using a computerized voice analysis program. Repeated-measures analysis of variance was performed to test differences between groups for each acoustic voice parameter. RESULTS: Vocal stability among the women who use oral contraceptives was significantly better than among those who did not use oral contraceptives (P < .05). Specifically, amplitude and frequency variations between successive vocal cycles were smaller in women using oral contraceptives in comparison with the control group (.24 dB versus .37 dB and .86% versus 1.27% for amplitude and frequency variations, respectively). CONCLUSION: Contrary to the reports of adverse effects that high-dose pills have on voice, low-dose oral contraceptives show a favorable influence on voice in young women.