Solving problems in organic chemistry often requires the consideration of reaction mechanisms. As such, much research has been devoted to the examination of how students consider mechanisms when solving various types of organic chemistry problems, such as predicting the products of a reaction or proposing a synthesis. This article provides a scoping review of this body of research, with a focus on the key themes in the research literature regarding students' problem solving with organic reaction mechanisms. We first review the literature focused on how students approach mechanism problems in organic chemistry and the common challenges students face with using the electron-pushing formalism. We then identify and synthesize the research findings related to four themes prevalent in the literature about students' mechanistic problem solving. The first two themes are concerned with common difficulties students demonstrate when solving mechanism problems: (1) solving problems with a product-oriented, rather than process-oriented, approach and (2) focusing on surface features rather than implicit properties of chemical structures and mechanisms. The second two themes involve the particularly challenging aspects of problem solving with reaction mechanisms: the need to (1) consider multiple representations and (2) reason with multiple variables. After discussing these themes, we review the research on how mechanistic problem solving develops through undergraduate and graduate school and then review the literature focused on using and developing authentic problem types to support students' learning. We conclude by synthesizing implications for teaching and supporting students' development of problem solving with organic reaction mechanisms.