The ability to self-regulate learning in Massive Open Online Courses (MOOCs) plays a crucial role in the success of learners. Previous studies indicated the positive impact of self-regulated learning (SRL) strategies on students' learning behaviours and academic outcomes in massive open online courses (MOOCs), yet empirical studies on the impact of an SRL strategy intervention during their learning in MOOCs on these strategies are still scarce. The purpose of this study was to investigate the impact of a self-regulated learning strategy intervention on students' SRL skills and explore their perspectives of the intervention after being taught the SRL strategies during their learning in MOOCs. The study was designed as a convergent parallel mixed methods approach in which the quantitative phase of the study employed pre- and post-questionnaire surveys to assess students' self-regulated learning abilities before and after the intervention, while semi-structured interviews were used in the qualitative phase to address students' perspectives of the effectiveness of the treatment. SPSS 25 was run to analyse the quantitative data from the surveys, and thematic analysis was employed for the qualitative data. The results indicated an increase in students' goal-setting and environmental structuring abilities, whereas the interviews underscored the importance of the intervention for students' learning in MOOCs.