This paper offers an historical overview of international mortality/healthcare classification systems, covering developments from the International List of Causes of Death (ILCD) through to the International Classification of Diseases (ICD). The ICD is a global data system established to classify diseases and mortality causes. The past few decades have seen a dramatic increase in use of the ICD, paralleling its improved efficiency and integration into the health information management (HIM) arena. The ICD, published by the World Health Organization (WHO) since 1984, is the successor to ICLD-5 and assigns codes to every health diagnosis. The 10th revision of the WHO International Statistical Classification of Diseases and Related Health Problems (ICD-10-CM) is the latest version, and the 11th is currently under development. A clinical classification and coding schedule is essential for improving and refining clinical data systems in numerous ways, including treatment selection, cause-of-death reporting, eligibility selection, the facilitation of health insurance claims, data storage, health service evaluation, health policy, the management of epidemiological diseases, resource allocation and the reduction of potential costs. All these contribute to proper development and planning within healthcare services. ICD has become the universal standard.