Citrate is commonly used as an anti¬coagulant during plateletpheresis procedure. The calcium chelating property of citrate may cause hypocalcaemia when the anticoagulated blood are returned to the donor’s circulation after selective removal of platelet. This study aims at investigating how regular plateletpheresis affects calcium level and bone density in the donors. Methods: A cross-sectional study was conducted among healthy donors at National Blood Centre, Kuala Lumpur, from 15th January till 31st March 2016. Donors were divided into two groups based on the frequency of plateletpheresis donation: low frequency group - donors who had donated less than 20 times, high frequency group - donors who had donated more than 50 times. Dual emission X-ray absorptiometry (DEXA) scan was performed to assess bone density. Pre-donation blood sampling was taken for albumin level. Calcium and magnesium levels were measured before and after donation. Results: Fifty donors participated in this study where the median age of participants was 35.0 years for low frequency and 45.2 years for high frequency group. There was no significant difference in the corrected calcium for both groups before and after plateletpheresis. However, the magnesium levels were significantly reduced in both arms (P