The purpose of this study was to determine the extent to which professional development on assessment for learning improves pre-service teachers' self-regulated learning. Helping students develop self-regulation abilities in learning and assessment remains difficult due to the widespread culture of summative assessment in teacher education. A one-group pretest-posttest quasi-experimental research design was utilized to explore the influence of professional development in implementing assessment for learning on pre-service primary mathematics teachers' self-regulated learning skills. Three mathematics teacher educators who offered the algebra course, as well as their 52 students who attended the course, engaged in a job-embedded, context-specific, and content-based comprehensive professional development and training program on assessment for learning. A paired sample t-test result demonstrated that the self-regulated learning skills of pre-service teachers after the intervention were significantly higher than their self-regulated learning skills before the intervention, and there was a statistically significant mean difference between pre- and post-measurements of each of the achiever levels. Nevertheless, a one-way ANOVA showed that there was no statistically significant mean difference in the self-regulated learning skills across achiever levels after the intervention. This study contributes to our understanding of the influence of enhanced implementations of assessment for learning on students' self-regulated learning skills.