BACKGROUND: Many researchers have pointed out the strong relationship between maternal psychological well-being and fetal welfare during pregnancy. The impact of music interventions during pregnancy should be examined in depth, as they could have an impact on stress reduction, not only during pregnancy but also during the course of delivery, and furthermore induce fetal awareness. OBJECTIVE: This study aimed to investigate the effect of music on maternal anxiety, before and after a non-stress test (NST), and the effect of music on the birthing process. MATERIAL AND METHOD: The four hundred and nine pregnant women coming for routine prenatal care were randomized in the third trimester to receive either music (n = 204) or no music (n = 205) stimulation during an NST. The primary outcome was considered as the maternal state anxiety score before and after the NST, and the secondary outcome was the birthing process. RESULTS: Before their NST, full-term pregnant women who had received music intervention were found to have a similar state-trait anxiety score to those from the control group, with 38.10 ± 8.8 and 38.08 ± 8.2, respectively (p = .97). After the NST, the mean state-trait anxiety score of each group was recorded, with results of 30.58 ± 13.2 for those with music intervention, and 43.11 ± 15.0 for those without music intervention (p < .001). In the control group, the NST was followed by a statistically significant increase in the state-trait anxiety score (38.08 ± 8.2 versus 43.11 ± 15.0, p < .001). However, listening to music during the NST resulted in a statistically significant decrease in the state-trait anxiety score of the study group (38.10 ± 8.8 versus 30.58 ± 13.2, OR = 0.87, p < .001). Furthermore, the first stage of labor was shorter in women who received music stimulation (OR = 0.92, p < .004). They also presented a more natural delivery beginning (spontaneous) and less medication (stimulated and induced) than those who were not stimulated musically, with statistically significant differences (p < .01). CONCLUSIONS: Prenatal music intervention could be a useful and effective tool to reduce anxiety in full-term pregnant women during an NST and improve the delivery process by reducing the first stage of labor in nulliparous women.