Background There is an ongoing debate on the effectiveness of suicidal behavior prevention measures in the military. The association of three widely used tools with severe suicide attempts was assessed in this setting. Methods Thirty-nine Israeli soldiers (59% males), mean age 19 yrs., who attempted suicide during military service were divided into two groups: severe (n = 14; 35.9%) and moderate suicide attempts, and were assessed using the Scale for Suicide Ideation (SSI), Suicide Intent Scale (SIS) and the Columbia Suicide Severity Rating Scale (C-SSRS). Results Seven items from the SSI (p = 0.008), two items from SIS and one item from C-SSRS were associated with severe suicide attempts. Kendall’s tau-b correlation with bootstrap demonstrated stability of these correlations. Conclusion Greater severity of suicidal ideation was associated with more severe suicide attempts. The combination of male gender, available firearms and current severe suicide ideation is high-risk danger sign in a military setting, even when reported intent to die is low.