This study aims (1) to analyze the contribution of prior knowledge to students' misconceptions in physics, (2) to analyze the contribution of learning motivation to students' misconceptions in physics, and (3) to analyze the contribution of prior knowledge and students' motivation to misconceptions experienced by students in physics learning. Correlational research is the type of research conducted in this research. A total of 222 class X high school students in the even semester of 2019/2020 in Nangapanda District are the population in this study. A total of 85 students were selected as the sample by using the proportional random sampling technique. Research data were collected through a physics concept understanding test to calculate prior knowledge and misconceptions, and learning motivation was collected through a learning motivation questionnaire. The data analyzed by regression in this study were students' prior knowledge, motivation, and physics misconceptions. The results showed (1) there was a 54.6% contribution of prior knowledge to misconceptions (p<0.05), (2) there was a 58.7% contribution of learning motivation to misconceptions (p<0.05), and (3) there was a contribution of prior knowledge and learning motivation. against misconceptions by 68.5% (p<0.05). This study concludes that prior knowledge and motivation contribute to students' misconceptions in physics learning.