This chapter reviews the traditional concept of multilingual lexicography and offers some examples of traditionally conceived multilingual lexicographic projects that are abundant in the era of the Internet: IATE; The Logos Dictionary; The Diccionari de la Llengua Catalana Multilingüe. Our analysis shows that this traditional approach is erroneous and does not help potential users. Consequently, we offer a different approach, which stems from our definition of multilingual lexicography as the theory and practice of unified and well-connected monolingual, bilingual and multilingual dictionaries using data from a multilingual database. These dictionaries are information tools that cover words, terms, facts, and/or things in several languages, have the same conceptualization at the pre-compilation phase, and make use of lexicographic and technological know-how. This allows (a) lexicographers to add new languages to the same information database from which new monolingual, bilingual and multilingual dictionaries can be extracted, and (b) users to retrieve connected data easily and to spot and understand possible similarities and differences among the several languages covered. We also illustrate the operational side of this definition in some of our accounting dictionaries.