Planning is an essential part of teachers' work that has consequences for students' learning. However, previous research shows that what it means to plan vary. To explore the meaning of planning from teachers' point of view, and to open up for planning as a situated and emotional process, an interview study with Swedish mathematics teachers was conducted. In the analysis, the theoretical concepts, meaning, and emotions were used as analytical tools to fill the gap identified in the review of previous research about planning. Findings reveal planning as a varied process in which teachers draw on different resources. Actors other than teachers influence both how planning is done and the mathematics teaching that is planned for. Findings also reveal that feelings, such as joy, shame, and insufficiency, are present in the process of planning. These feelings sometimes have consequences for decisions teachers make about their mathematics teaching.