Background The aim of this systematic review was to examine the classification of calls for suicidal behavior in emergency medical services (EMS). Methods A search strategy was carried out in four electronic databases on calls for suicidal behavior in EMS published between 2010 and 2020 in Spanish and English. The outcome variables analyzed were the moment of call classification, the professional assigning the classification, the type of classification, and the suicide codes. Results Twenty-five studies were included in the systematic review. The EMS classified the calls at two moments during the service process. In 28% of the studies, classification was performed during the emergency telephone call and in 36% when the professional attended the patient at the scene. The calls were classified by physicians in 40% of the studies and by the telephone operator answering the call in 32% of the studies. In 52% of the studies, classifications were used to categorize the calls, while in 48%, this information was not provided. Eighteen studies (72%) described codes used to classify suicidal behavior calls: a) codes for suicidal behavior and self-injury, and b) codes related to intoxication, poisoning or drug abuse, psychiatric problems, or other methods of harm. Conclusion Despite the existence of international disease classifications and standardized suicide identification systems and codes in EMS, there is no consensus on their use, making it difficult to correctly identify calls for suicidal behavior.