The process of academic writing is a highly demanding mental activity that presents a number of difficulties for students, especially when it comes to L2/FL (second/ foreign language) writing. The study employs the social-cognitive model of writing to explore the issue of students’ self-regulated learning (SRL) in English as a foreign language (EFL) writing, with a special emphasis on the most important processes and strategies that may influence the quality of writing performance. We also wanted to explore whether there is an improvement in the quality of writing performance due to regular students’ exposure to EFL learning at the university levels. The quantitative part of the study involved 104 students (53 undergraduates and 51 graduates), while the qualitative part focused on two groups of higher and lower proficiency writers. The quantitative part of the study pointed out a significant difference between the first and second measurement points in the quality of students’ writing performance both at the undergraduate and graduate levels of study. Students in second measurement point had a better writing performance compared to the ones in the first measurement point. The qualitative research results showed that higher proficiency writers exhibited better SRL processes compared to lower proficiency writers. The research findings suggest that the students’ writing proficiency benefits from incorporating more SRL processes in EFL learning/teaching in the Croatian educational context.