Aims: To investigate the risk factors of intra-amniotic infection (IAI) related to induction with single-balloon catheter (SBC). Methods: A retrospective, case-control study including 58 cases of IAI patients who underwent induction with SBC was conducted in Women’s Hospital, School of Medicine, Zhejiang University. For each case, 8 women who delivered during the same month and had no infection after SBC induction were selected for control. Results: Compared with the control group, the IAI group had a higher rate of nulliparity (87.93 vs. 70.69%; p = 0.006), BMI > 30 kg/m2 (29.31 vs. 15.95%; p = 0.011), and amniotic fluid index (AFI) < 8 cm (32.8 vs. 15.1%; p = 0.001). The diameter of cervical dilatation when membranes ruptured in IAI group was smaller than that in the control group (2.0 [1.5] vs. 3.0 [8.0] cm; p < 0.001). Time from start of induction to vaginal delivery was longer than that in the control group (47.0 [19.75] vs. 27.0 [16.0] h; p < 0.001). After logistic regression, the 5 factors associated with IAI for those who underwent SBC induction were nulliparity, BMI > 30 kg/m2, AFI < 8 cm, diameter of cervical dilatation < 3 cm when membranes ruptured and time from start of induction to vaginal delivery of more than 48 h. Conclusions: Focus on these risk factors could result in earlier prophylaxis so that the incidence of IAI could be reduced.