This empirical study examined the perceptions and experiences of nine Thai college student writers' expression of emotions in poetry, narrative, and opinionated writing written in their first (L1) and second (L2) languages: Thai and English. The study focused on the participants' perspectives in order to gain more understanding of the phenomenon of expressing emotions in writing in different languages. The participants were nine Thai college students who attended a public university in Thailand. The data, gathered over three months, included 54 written responses and 36 interview sessions. The written responses included poems, narrative stories, and opinionated writing both in Thai and English. The interviews were conducted in Thai, transcribed, and translated into English. The interviews were then analyzed from two aspects: focusing on each individual's perceptions and experiences and focusing on genre writing and their emotionality writing experiences. This study's analysis suggested that the participants had positive responses to the written tasks when expressing emotions through different genres in L1 and L2. It also showed that emotions are one of the crucial elements in participants' writing experiences and that cultural and linguistic identities played important roles in the tasks of emotionality writing in both languages. The emotionality writing helped L2 learners gain meta-linguistic awareness of L1 and L2 and reflect on their language learning and personally significant experiences. Through that awareness, L2 learners could become educators for others who want to learn about their L1. The emotionality written tasks allowed the participants to reflect on their language learning and personally significant experiences. This study argued that emotionality writing should be encouraged in L2 writing classrooms and addressed the ramifications of expanding of L2 writing on a pedagogical level. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]