The number of words international students know is quite important in using both productive and receptive skills. Lewis (1993, s. 89) states that “vocabulary is the core or heart of language”. In order to determine which words students should acquire initially, different word lists have been prepared based on different corpuses. The most popular of these are general and academic word lists. The first includes the most frequently used words in daily life, whereas the second includes those most frequently used in academic texts. There are many word lists prepared by researchers in languages widely taught as a foreign language, i.e. English. However, in Turkish these lists are very few. The aim of this study was to determine the vocabulary load of the textbooks used in common courses at faculty of economics and administrative sciences and compare these words with those in İstanbul, Turkish teaching books for foreigners. The present study tries to seek answers to the following questions: 1. How many words do international freshman students need to know in order to understand the textbooks of common courses at faculty of economics and administrative sciences? 2. How many of these words are the same with those taught in İstanbul, Turkish teaching books for foreigners? 3. What are the high frequency words that are found in the corpus but not among the first 2.000 words of Göz (2003)? 4. What is the coverage of the first 2.000 words of Göz (2003) in the corpus? A corpus of 620.554 words was formed consisting of four textbooks of these courses: Introduction to Economics, Basic Concepts of Law, General Accounting and Constitutional Law. The books were chosen with the help of two professors working at the same institution with the researcher. All the books were scanned into a PDF file and then converted into a Word file using AbbyFine Reader 10 program.On the Word file, the following procedures were carried out: a) Prefaces, contents, references, appendices, headers, letters in front of the headlines and paragraphs, all the numbers and proper names, tables consisting of numeric data, all the web internet address beginning with “www” orhttps:// and words that were not correctly scanned by AbbyFine Reader 10 were deleted. b) AntWordProfiler recognizes every data between a space as a new word, so, reduplications ( i,e. ufak tefek, süslenip püslenmek, eski püskü, satın almak) whose first , second or both items are not found in Turkish dictionary were combined and made as one word.c) All the abbreviations were expanded to their full forms. At the end of these procedures 532.934 words remained in the corpus and these words were analysed.The analysis was carried out using AntWordProfiler (Version 1.4.0) developed by Anthony (2014). The software has two sections for two different data to be uploaded. The corpus is uploaded into the first section and the word list, with which the corpus will be analysed, is uploaded into the second section. The word list has to include all the lemmas and tokens that the corpus includes. This list was prepared beforehand. In the present study, as in most Turkish frequency studies, each base was accepted as a separate word in accordance with the recommendation of Kurudayıoğlu and Karadağ (2005). In order to answer the second question of the study, the words of İstanbul, Turkish teaching books for foreigners (five books at A1, A2, B1, B2 and C1 levels) were taken from the PhD. dissertation of Göçen (2016). AntWordProfiler analyses only the text files, so, the corpus and the word lists of the corpus and İstanbul were transformed into text files using Unicode (UTF-8) format. The study revealed that there were 8.050 words in four textbooks. Laufer (1989) says that a reader should know % 95 of the words in a text to comprehend it without using a dictionary. This means 1 unknown word in every 20 words. According to this criteria, in order for international students to understand these textbooks without looking up a dictionary, they should know at least 7.648 of 8.050 words. When the words in the corpus are compared with those in Istanbul, Turkish teaching books for foreigners, it was seen that 3.551 (44%) of the 8.050 words in the corpus are taught in İstanbul. Even if we assume that international students have learned all the words in the set, it means that they