Grounded in a social penetration perspective, this exploratory study aspires to examine the impact of self-disclosure on intercultural friendship development between Taiwanese and native English speakers by a section of the following populations: (a) Taiwanese sojourning in the US, (b) native English speakers sojourning in Taiwan, and (c) Taiwanese in Taiwan. This research employed a triangulation of quantitative surveys and qualitative interviews to answer the proposed research questions and hypothesis regarding four dimensions and six topics of self-disclosure. Consistent with the quantitative results, the five themes that emerged from the qualitative analysis indicate both unique challenges in self-disclosing to intercultural friends and a positive association between self-disclosure and cultural adaptation. Additionally, this study highlights the role of self-disclosure in the four identified stages of intercultural friendship development. Finally, findings from this study have implications for the social penetration theory, anxiety/uncertainly management theory, and theory of adaptation in intercultural dyads.