Background: The absence of agreed-upon terminology, definitions, and operational classifications has hampered research in the field of suicidology for many decades. Aims and Method: We systematically reviewed contemporary classifications of suicidal behavior using the scope of the classification (comprehensive vs. restricted or single behaviors), and the presence or absence of a classification scheme and an operational definition of intent as features to enable analysis and comparison. Results: A chronological perspective shows that classification systems tend to be more and more precise and operational for clinical and research field work. However, on an international level, the development of classifications appears to precede the establishment of agreed-upon definitions and terms to describe suicidal behavior. Limitations: The review was conducted in English only. Conclusion: Universal agreement on definitions and terms for suicidal behavior should precede the development of classifications.