The present study aimed to examine the relationship between the voting behavior of Japanese teenage voters and their political interests and sense of political efficacy. 225 undergraduate students, aged 18 to 19 years old, were asked to answer the questionnaire which included an item concerning participation in voting in the 2016 national elections, 8 items concerning political interests, and 8 items concerning sense of political efficacy. Comparing the scores on the subscales on political interests and political efficacy between those who voted and did not vote, a significant difference was found on the subscales on political interests, but not on political efficacy. Those who voted were more interested in both “political issue” and “political information” than those who did not vote. Results suggested that the political participation of teenage voters could be promoted by enhancing their political interests.