This study extends prior scholarship on the role of self-disclosure in relationship development on the Internet in three different cultures: Korea, Japan, and the United States. The duration of the online relationship was considered as well as the two typical dimensions (i.e., breadth and depth) of self-disclosure. The results suggest some cross-cultural differences and similarities in the associations between self-disclosure and relationship qualities. For Americans, Japanese, and Koreans, self-disclosure was directly associated with online relationship development. However, the relationship between self-disclosure and trust was positive only for Americans.