Diphyllobothrium latum is one of the longest intestinal tapeworms in humans and has numerous reservoir hosts, such as dogs, cats, foxes, and other wild canines [1]. In the past, the first case of D. latum infection was reported in 1919 by the recovery of eggs in 2 patient’s feces living in Jinju, a southern area of Korea [2]. D. latum infection diagnosed by adult tapeworm recovery was reported for the first time in 1971 [3]. The rapid change of life quality the Republic of Korea with the increased consumption of expensive raw fish is suggested to be a factor for an increase in D. latum infections in young ages. A total of 41 cases have been diagnosed by the adult worm from 1971 to 2007 [4], and additional 3 cases diagnosed by colonoscopy were reported from 2007 to 2011 [5-7]. Herein, we report 4 cases of D. latum infection as 45th to 48th case in the Republic of Korea.