There is a limitation to estimate vitamin B₁₂ intake due to the lack of data on vitamin B₁₂ content of Korean commercial foods. In this study, vitamin B₁₂ content was determined in favorite Korean restaurant foods, convenient or instant foods, fast foods and bakery products through a modified microbioassay using Lactobacillus delbrueckii ATCC 7830. Bulgogi and seafood & green pepper griddle had high vitamin B₁₂ content, 3.50 and 2.96 µg/100 g, respectively. Pork suyook, pork griddle and pollack griddle had 0.48, 0.31 and 0.32 µg/100 g of vitamin B₁₂, respectively. In stew, soft-tofu stew with seafood and doenjang stew with seafood had relatively high vitamin B₁₂ content, 1.93 and 1.44 µg/100 g, respectively. Bibimbap and 4 different types of rice porridge, beef & mushroom, chicken & ginseng, seafood or abalone, had 0.36, 0.08, 0.09, 1.64 and 0.13 µg/100 g of vitamin B₁₂, respectively. One serving of haejanggguk, yookejang, chuotang and galbitang had 5.97, 2.04, 2.63 and 1.91 µg of vitamin B₁₂, respectively. One serving of samgetang and sulongtang had 2.89 µg and 6.64 µg of vitamin B₁₂. In noodles, one serving of cram noodle soup, bibim-nangmyeon, and mul-nangmyeon had 18.8, 1.21 and 0.38 µg of vitamin B₁₂, respectively. One regular gimbap and one triangle gimbap contained 1.09-2.53 and 0.54-1.11 µg of vitamin B₁₂, respectively. One cheese-burger, chicken-burger and bulgogi-burger had 0.76, 0.62 and 0.54 µg of vitamin B₁₂, respectively. A plain bagel and a waffle contained 0.13 and 0.17 µg/100 g of vitamin B₁₂, respectively. Ready-made tomato sauce or cream sauce for spaghetti in a retort pouch contained only a trace of vitamin B₁₂. In conclusion, these results should contribute to improving the present food vitamin B₁₂ content database, most of which were cited from foreign data, thereby it could be helpful to estimate the vitamin B₁₂ intake of Koreans more accurately than before. It will also provide new information for dietary education related to vitamin B₁₂ and health.