Background: Calcium carbonate (CaCO 3 ) is the most used phosphate binder among chronic kidney disease (CKD) patients in Malaysian hospitals. Hence, it is crucial for patients to have adequate knowledge and practice of CaCO 3 administration for effective phosphate-lowering therapy. Patient education serves as a keystone in inducing positive changes in patients' knowledge and practices. Aim: To evaluate the impact of pharmacist-led education sessions (PLES), an educational approach in improving patients' knowledge and practices regarding CaCO 3 administration. Method: A total of 57 CKD patients prescribed CaCO 3 were enrolled in a prospective, cross-sectional study at the nephrology unit of a public-funded hospital in Penang, Malaysia. Their baseline knowledge and practices of CaCO 3 administration were assessed using a validated questionnaire consisting of five questions in the knowledge and practice sections, respectively. A patient's total score of less than seven was considered unsatisfactory, and these patients were provided PLES by pharmacists experienced in kidney health. After an interval of 4 weeks, patients were reassessed with the same set of questions. Results: The median (interquartile range) knowledge and practice scores before PLES were 0 (0, 1) and 3 (3, 5), respectively, while the overall score was 4 (3, 5). A significant improvement was demonstrated after PLES in the knowledge score (3 (2, 4) (p < 0.001)), practice score (5 (5, 5) (p < 0.001)) and overall score (7 (6, 9) (p < 0.001)). All the questions assessing CKD patients' knowledge and practices showed significant improvement after PLES. Conclusion: Pharmacist-led education sessions have an impact on improving CKD patient's knowledge and practices regarding CaCO 3 administration.