Writing and emotion in Spanish second and heritage language classrooms is less studied than in English and English to Speakers of Other Languages (ESOL) contexts (Manchón & de Haan, 2008). However, some researchers have started to study writing in non-English contexts and have examined affective factors such as motivation (Hanson, 2019) and anxiety (Tallon, 2006; Xiao & Wong, 2014). This study aimed to document students’ levels of writing anxiety and enjoyment in both Spanish as a second language (L2) and Spanish as a heritage language (HL) classrooms and identify any explanatory variables of said emotions.A total of 86 participants from the University of California, Davis (41 L2 and 45 HL students) completed pre- and post-questionnaires, and 10 students, five from each track (L2 and HL), participated in follow-up, semi-structured interviews. Students’ levels of writing anxiety and enjoyment were measured by surveying students using the Second Language Writing Anxiety Inventory (SLWAI) scale (Cheng, 2004) and an adapted version of the Foreign Language Enjoyment scale (Dewaele & Dewaele, 2014), both consisting of Likert-scale questions. The possible predictors of writing anxiety and writing enjoyment were examined qualitatively via the semi-structured interviews, and quantitatively by using a third questionnaire developed by the researcher for multiple regression analyses. Results showed that both groups’ writing anxiety significantly decreased, and their writing enjoyment significantly increased after just one writing-intensive term. Confidence and transparency positively correlated with low writing anxiety for both groups. The HL learners’ results showed that high proficiency and writing with informal varieties had more impact on reducing writing anxiety while for L2 learners, it was peer feedback and completing informal, low stakes assignments. Quality feedback greatly mattered to both groups of learners and significantly correlated with high writing enjoyment. While the teacher and topic presented significant quantitative correlations with writing enjoyment for the HL learners, both groups voiced the importance of the topic and teacher in the qualitative data. Developing a more comprehensive understanding of second and heritage language writing anxiety and enjoyment in languages other than English will provide important insight regarding language education in order to better foster positive language learning and writing experiences. Improved language learning and writing experiences could in turn result in more students pursuing further Spanish language study and increased biliteracy.