Algebra I is considered a gatekeeper course for higher education and high-paying jobs, yet many students find themselves struggling with learning it. Prior research links intrinsic motivation for learning math with mathematics achievement, particularly during adolescence. The current study measured middle school students’ interest in algebra and their procedural skills across the span of an algebra unit to determine whether students who show declines in algebraic problem-solving also show a decline in a particular type of intrinsic motivation – interest in algebra. Pretest and posttest scores were used to categorize participants into those who showed declines in problem-solving skills and those who did not. Of the overall sample (N = 367), a group of 25 students showed declining skills over the course of the unit. These students also showed significant declines in interest in mathematics from pre- to post-test in comparison to students who did not show procedural declines.