The objective of this study is to expand teachers' knowledge base of assessment in teaching by exploring pre-service language teachers' construct of grading literacy during their pedagogical studies and immediately after. We conceptualize pre-service language teachers' grading literacy with a literature-based flow model of decision-making comprising six major phases. These involve (1) mobilizing grading related knowledge, skills and dispositions, (2) distinguishing relevant assessment events, (3) identifying and filing evidence, (4) interpreting assessment rubrics, (5) making the grading decision, and (6) communicating it to stakeholders. The decision trajectory is constrained by individual and social factors. The research questions address pre-service teachers' perceptions of the multiple components, primarily the evidence base of a grade. The data comprise survey responses (n = 131) and interview data (n = 26) from three universities, one in Finland and two in Sweden. Regarding the factorial structure, variables incorporating process and disposition aspects provided the strongest explanatory the most frequently attended grading evidence comprises written and oral tests. Pre-service teachers in Finland and Sweden differ with regard to most aspects of what evidence they base their grading on. The interview responses confirm pre-service teachers' high awareness of the complex nature of grading and the responsibility attached to the endeavour. Based on the findings we propose recommendations for teacher education programs to broaden and enrich pre-service teachers' grading practice to encompass processual and progress aspects. Increased attention should be paid to practical implementation of grading standards and guidelines in interpreting and justifying grading decisions.