Background: Sclerostin (sScl), an osteocyte-derived glycoprotein acts as a soluble inhibitor of the Wnt signaling pathway and bone formation. Its serum levels increase with the progression of CKD. The present study investigated the effect of hemodiafiltration (HDF) on sScl and bone specific alkaline phosphatase (BS-AP) in comparison with high flux hemodialysis (HF-HD). Methods: a prospective study was conducted upon 32 ESRD patients; 16 on regular HF-HD and 16 shifted to 3 months of HDF. Results: There was a significant reduction of predialysis sScl and BS-AP with a significant increase in sScl reduction ratio in the HDF group after 3months. SScl had a significant positive correlation with total but not BS-AP. Conclusion: sScl and BS-AP significantly decrease but are poorly correlated with each other in HDF. So either sScl reduction does not translate into better bone turnover or the BS-AP is not a suitable biomarker to assess bone turnover in HDF.