Introduction Suicidal ideation (SI) has numerous limitations in predicting suicidal behavior. The Suicide Crisis Syndrome (SCS) is proposed as an alternative method of detecting risk. This study compares the relative utility of SI and SCS in statistically predicting SI and behaviors at one-month follow-up. Methods 382 psychiatric patients (98 inpatients, 284 outpatients) completed baseline measures and provided information about suicide-related outcomes one month later. Participants were grouped based on responses to measures assessing SCS and SI. Results Rates of follow-up suicidal behavior were significantly higher among those reporting both SCS and SI (22.2%) than those reporting SI alone (6.0%) or neither SCS nor SI (0.9%). SCS alone (8.3%) had descriptively, but not statistically, higher rates of suicidal behavior than those with neither SCS nor SI, and did not differ from SI alone and the combination of SCS and SI. Those reporting SI—with and without SCS—had higher levels of follow-up suicidal thoughts than those without SI. Conclusion The SCS was equivalent to SI, and incrementally informative alongside SI, in detecting individuals at risk of future suicidal behavior, whereas SI was more strongly related to future SI than SCS. The combination of SCS and SI may be clinically useful in detecting individuals who are at risk for suicide.