This study examined the impact of Problem-Based Learning (PBL) on students' English speaking proficiency and learning attitudes in IELTS preparation classes. Grounded in learner-centred and communicative teaching theories, the study designed learning activities based on real-life situations and assessed their effects on IELTS Speaking performance. A quasi-experimental design was employed with an experimental and a control group. Quantitative data were collected through pre- and post-tests and questionnaires, analyzed using paired-sample t-tests. Qualitative data from open-ended questions were examined using thematic analysis. Results showed that students in the experimental group improved in fluency, vocabulary, and pronunciation, and demonstrated more positive attitudes in behavioural, cognitive, and affective aspects. The findings confirm the effectiveness of integrating PBL into IELTS preparation programs.