This explanatory sequential mixed methods study investigated the writing feedback perceptions of middle and high school students (N = 598). The predictive and mediational roles of writing self-efficacy and perceptions of writing feedback on student writing self-regulation aptitude were examined using mediation regression analysis. To augment the quantitative findings, the explanations students provided for either liking or disliking writing feedback were explored using open-ended questions. Quantitative findings revealed that students' perceptions of the feedback they receive about their writing partially mediated the relationship between writing self-efficacy and writing self-regulation aptitude. Qualitative data suggested ways in which students perceive writing feedback--both positive and negative. Collectively, the quantitative and qualitative data illustrate the influential role writing feedback perceptions plays in middle and high school student writing motivation and self-regulation beliefs.