<b><i>Background:</i></b> Women with high-risk pregnancy experience anxiety and low mother-fetal attachment when faced with signs of danger and health problems. This study aimed to investigate the effects of lullaby intervention on anxiety and prenatal attachment in women with high-risk pregnancy. <b><i>Materials and Methods:</i></b> This randomized controlled trial was conducted in the perinatology clinic of a state maternity hospital in Turkey. Seventy-six women with high-risk pregnancy were included. The intervention group listened to lullabies for 20 min once a day, and accompanied by lullabies touched their abdomen and thought about their babies, but the control group did not. Data were collected using the Pregnant Information Form, the State Anxiety Inventory, and the Prenatal Attachment Inventory. <b><i>Results:</i></b> Baseline anxiety did not differ in the intervention versus control group (47.83 ± 10.74 vs. 44.10 ± 8.08, mean difference 3.73 [95% Cl –1.18 to 8.64], <i>p</i> = 0.13), but after the 2nd day lullaby intervention anxiety was lower in the intervention group versus control group (33.66 ± 9.32 vs. 43.06 ± 8.10, mean difference –9.40 [95% Cl –13.91 to –4.88], <i>p</i> < 0.01). Baseline prenatal attachment did not differ in the intervention versus control group (56.03 ± 10.71 vs. 53.86 ± 9.98, mean difference 2.16 [95% Cl –3.18 to 7.51], <i>p</i> = 0.42), but after the 2nd day lullaby intervention prenatal attachment was higher in the intervention group versus control group (66.70 ± 7.60 vs. 54.36 ± 9.52, mean difference 12.33 [95% Cl 7.87 to 16.78], <i>p</i> < 0.01). In the within-group analysis the intervention group had lower anxiety and better prenatal attachment (<i>p</i> < 0.01), but not in the control group (<i>p</i> > 0.05). <b><i>Conclusion:</i></b> Lullaby intervention can play an effective role in reducing anxiety and improving prenatal attachment. The use of this integrative, noninvasive, non-pharmacologic, time-efficient, and natural intervention is suggested in the care of pregnant women.