This study aims at specifying cultural words in teaching Turkish as a foreign language according to their proficiency levels (A1/2, B1/2, and C1/2) and analyzing the difference between the proficiency levels of these cultural words in terms of their frequency. For this purpose, a cultural corpus of 112.350 tokens in total has been created based on written and oral cultural texts. In this cultural corpus, nouns and verbs in the first 2000 in terms of their frequency have been compared with nouns and verbs in the most common 2000 Turkish words, and nouns and verbs that are not in the most common 2000 Turkish words have been marked as cultural words. Then, the cultural words have been compared with the textbooks used in teaching Turkish as a foreign language. The proficiency levels of their English equivalents in Cambridge Learner's Dictionary and the context in which they are used in the corpus have been checked and listed according to their levels. Finally, the list has been edited according to the opinions of two experts teaching Turkish as a foreign language at university level. The differences in the frequency of cultural words according to their proficiency levels have been analyzed using Kruskal-Wallis and Mann-Whitney U tests. Findings show that there is a statistically significant difference between A1 and A2; A2 and B1; B1 and B2; C1 and C2 levels of the cultural words in terms of frequency, whereas there is no significant difference between cultural words at B2 and C1 levels in terms of frequency. In these findings, it has been seen that the most cultural words are at B1 level in terms of number and concept diversity, and it has been concluded that B1 level could be a threshold in the teaching of cultural words.