In situations where death by suicide is a major global issue and effective prevention and management approaches are lacking, acupuncture improves some risk factors for suicide, including depression, and it has been used for a long time in clinical settings. Herein, we aimed to assess the effectiveness and safety of acupuncture in the treatment of suicidal behaviors. Fourteen electronic databases were searched for studies published up to 7 September 2022. Original interventional studies of acupuncture in suicide prevention were included. The primary outcome was the validated measure of suicidal ideation. The risk of bias in the included studies was assessed using an appropriate assessment tool. Due to the heterogeneity of the included studies, only qualitative analyses were conducted. Eight studies on manual acupuncture (50%), electro-acupuncture (37.5%), and acupressure (12.5%) were included. In particular, three studies (37.5%) used the National Acupuncture Detoxification Association protocol to stimulate the bilateral sympathetic, Shenmen, kidney, liver, and lung auricular points. Acupuncture was effective in direct and indirect outcomes related to suicidal behavior, not only for participants with suicidal behavior, but also for those with other conditions, including depression. A decrease in salivary cortisol was the only biological indicator of acupuncture in patients with suicidal ideation. However, the methodological quality of the included studies was not optimal. In conclusion, acupuncture may reduce the risk of suicidal behavior in clinical and non-clinical populations. Owing to clinical heterogeneity, low methodological quality, and the small number of included studies, further high-quality studies should assess the effectiveness of acupuncture.