There is a limitation to estimate vitamin $B_{12}$ intake due to the lack of data on vitamin $B_{12}$ content of Korean commercial foods. In this study, vitamin $B_{12}$ 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 $B_{12}$ content, 3.50 and $2.96{mu}g$/100 g, respectively. Pork suyook, pork griddle and pollack griddle had 0.48, 0.31 and $0.32{mu}g$/100 g of vitamin $B_{12}$, respectively. In stew, soft-tofu stew with seafood and doenjang stew with seafood had relatively high vitamin $B_{12}$ content, 1.93 and $1.44{mu}g$/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 $0.13{mu}g$/100 g of vitamin $B_{12}$, respectively. One serving of haejanggguk, yookejang, chuotang and galbitang had 5.97, 2.04, 2.63 and $1.91{mu}g$ of vitamin $B_{12}$, respectively. One serving of samgetang and sulongtang had $2.89{mu}g$ and $6.64{mu}g$ of vitamin $B_{12}$. In noodles, one serving of cram noodle soup, bibim-nangmyeon, and mul-nangmyeon had 18.8, 1.21 and $0.38{mu}g$ of vitamin $B_{12}$, respectively. One regular gimbap and one triangle gimbap contained 1.09-2.53 and $0.54-1.11{mu}g$ of vitamin $B_{12}$, respectively. One cheese-burger, chicken-burger and bulgogi-burger had 0.76, 0.62 and $0.54{mu}g$ of vitamin $B_{12}$, respectively. A plain bagel and a waffle contained 0.13 and $0.17{mu}g$/100 g of vitamin $B_{12}$, respectively. Ready-made tomato sauce or cream sauce for spaghetti in a retort pouch contained only a trace of vitamin $B_{12}$. In conclusion, these results should contribute to improving the present food vitamin $B_{12}$ content database, most of which were cited from foreign data, thereby it could be helpful to estimate the vitamin $B_{12}$ intake of Koreans more accurately than before. It will also provide new information for dietary education related to vitamin $B_{12}$ and health.