This qualitative study investigates the motivation to write of four students in an upper middle class suburban community in the northeastern part of the United States. Utilizing a multiple case study approach, this current research focused on the interplay of the individual within the socio-cultural environment, using Bronfenbrenner's (1979) ecological systems framework and Bourdieu's (1997) notion of habitus as analytical lenses. This study moved beyond a linear model of motivation to account for the complexities of interacting motivational processes and focused on student perspective, noticeably absent from the motivation research literature. Findings suggest that five factors contribute to a student's motivation to write. First, a student's habitus, and specifically its concordance or discordance within a certain context, profoundly affects his or her motivation to write. Second, motivation to write is informed by a student's identity within a certain context. Third, social and contextual supports can facilitate motivation to write, depending upon a student's identity and habitus. Fourth, a student's perception of autonomy, informed by his or her habitus and identity and promoted by a feeling of agency, could motivate a student to write. Fifth, students could be motivated to write to explore the complex emotions encountered in the social world and across various contexts. Implications suggest that taking into account in-school writing experiences of high school students can inform educators about changes necessary to the design and implementation of writing instruction and assessment practices.