Currently, capsule cigarettes have been introduced by tobacco industries and their sales have increased exponentially. However, the capsule flavoring ingredients and their safety are still unknown. Although the contents of menthol and other ingredients directly added to cigarettes have been determined extensively, no analogous study exists for menthol-containing cigarette capsules. Basic physical properties of capsules in all 31 different capsule cigarettes commercially available in Korea were investigated, and their menthol contents were determined in this study. Other ingredients in these capsules were also qualitatively analyzed; methyl octanoate, menthone and isopulegol as well as menthol were detected in all the capsules. There is considerable variability in basic physical properties and menthol contents of cigarette capsules depending on their brand styles. The menthol contents of capsules and whole cigarettes are similar or higher than those previously reported for conventional menthol cigarettes. This is the first report on the physical properties of capsules and the fact that a wide range of menthol contents in capsule cigarettes, regardless of flavor types, allows smokers to select menthol content to their liking.