Standardization of medical terminology is essential in data transmission betweenhealth care institutes and in maximizing the benefits of information technology.The purpose of this study was to standardize medical terms for laboratory observations. During the second year of the study, a standard database of concept names for laboratory terms that covered those used in tertiary health care institutes and reference laboratories was developed. The laboratory terms in theLogical Observation Identifier Names and Codes (LOINC) database were adopted andmatched with the electronic data interchange (EDI) codes in Korea. A public hearing and a workshop for clinical pathologists were held to collect the opinions of experts. The Korean standard laboratory terminology database containing six axial concept names, components, property, time aspect, system (specimen), scale type, and method type, was established for 29,340 test observations. Short names and mapping tables for EDI codes and UMLS were added. Synonym tables were prepared to help match concept names to common terms used inthe fields. We herein described the Korean standard laboratory terminology database for test names, result description terms, and result units encompassingmost of the laboratory tests in Korea.