Background Deviated noses and asymmetric nostrils can be corrected using corrective rhinoplasty. However, after proper correction, adjacent facial mimetic muscles can cause recurrence of asymmetry because of preoperative habits. Objectives We performed this study to investigate the effects on botulinum toxin on the prevention of recurrence of asymmetry after corrective rhinoplasty. Methods From January 2016 to December 2019, 60 patients underwent corrective rhinoplasty and 30 received botulinum toxin type A injection (Botulax; Hugel Co.) at the depressor septi nasi and levator labii superioris alaeque nasi muscles, bilaterally. Vertical and horizontal deviations were compared preoperatively and postoperatively. Results Postoperative vertical deviation was 0.20° ± 0.65° in the botulinum toxin–injected group and 1.20° ± 0.53° in the control group (P < 0.0001). Horizontal deviation was 0.80° ± 0.52° in the botulinum toxin–injected group and 2.18° ± 0.42° in the control group (P < 0.005). Differences between preoperative and postoperative vertical deviations at 6 months were 2.30° ± 0.03° in patients who received botulinum toxin injection and 1.10° ± 0.22° in controls (P < 0.005). Conclusions Botulinum toxin effectively restricted the paranasal muscles without any significant adverse events. We recommend injecting botulinum toxin after corrective rhinoplasty to prevent recurrence of deviation by facial mimetic muscles.