LOINC is emerging as the standard for laboratory result names, and there is great interest in mapping legacy terms from laboratory systems to it. However, the mapping task is non-trivial, requiring significant resource commitment and a good understanding of the LOINC identifying attributes for the laboratory result names. Because the number of results in a laboratory system may range from around 500 to 2000 or more, manual, one-by-one matching, even with the aid of the RELMA matching tool provided by LOINC, is time consuming and laborious. Moreover, human variation may introduce mapping inconsistencies or errors. Through our experience mapping the results from a variety of laboratory systems to LOINC, an automated mapping method has been developed and is described in this paper. This method allows for data from the laboratory information system to be provided in a manner familiar to the submitting technician, and makes use of parsing and logic rules, combined with synonyms, attribute relationships and mapping frequency data, to perform automated matching to LOINC.