Objective: Kidney osteodystrophy is a condition that both reduces the quality of life and shortens the life span in patients with chronic kidney disease. Lanthanum carbonate is a phosphorus-binding agent that forms very tight complexes with phosphate ions, has low systemic absorption potential, and does not contain calcium and aluminum. The aim of this study was to evaluate the efficacy of lanthanum carbonate in patients with resistant hyperphosphatemia. Methods: One hundred four hemodialysis patients (44 females and 60 males; mean age: 59.5 ± 4 years) whose serum phosphorus level was above 6 mg/dL despite the use of phosphorus-binding drugs (calcium acetate, calcium carbonate, and/or sevelamer) were included in this study. The patients were followed prospectively for 6 months. Results: Twenty (19.2%) patients included in the study could not use the drug regularly due to difficulties in using it and nausea, while 84 (28 females and 56 males) patients used the drug regularly for 6 months. Lanthanum carbonate was used at a dose of 3 χ 750 mg in 37 patients and 3 1000 mg in 47 patients. While 72.6% of the patients used the drug by mixing it with food, the rest drank it with water. The most common side effects were nausea, constipation, and itching. Four different centers from 3 cities in Turkey participated in the study. When the patients who used it regularly were evaluated, after lanthanum carbonate use, the mean phosphorus level decreased from 6.9 ± 0.7 mg/dL to 5.97 ± 0.9 mg/dL (P =.02). The levels of calcium-phosphorus products were 62.12 ± 9.89 before lanthanum carbonate treatment and 57.6 ± 11.52 after treatment (P =.023).The levels of. It was observed that the mean parathormone levels decreased from 657 ± 48 pg/mL to 521 ± 36 pg/mL after treatment (P =.031). While none of the patients could take vitamin D due to hyperphosphatemia before the treatment, 52 patients could use vitamin D together with lanthanum carbonate. When 36 patients whose serum phosphorus level decreased with treatment but did not fall below 5.5 mg/dL were examined, it was observed that the mean parathyroid hormone level (708 ± 27 vs. 558 ± 30 pg/mL, P =.041) and the rate of patients using cinacalcet were higher in this group (41% vs. 8%). Conclusion: We found that serum phosphorus, calcium-phosphorus products, and parathyroid hormone levels decreased significantly with lanthanum carbonate treatment in patients with resistant hyperphosphatemia. As a result of our findings, we think that resistant hyperphosphatemia can be effectively treated with lanthanum carbonate in most hemodialysis patients without severe hyperparathyroidism.