Background:Recently the use of single donor platelet (SDP) concentrates has grown steadily due to its employment in chemotherapy protocols. Technical advances in automated cell separators have substantially improved the productivity and quality of the collection of apheresis platelets. Methods: We prospectively studied 90 healthy donors who volunteered for plateletpheresis. We compared the preand post-plateletpheresis haematological values, namely, haemoglobin (Hb), haematocrit, platelet count, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, platelet distribution width (PDW), red blood cell count, white blood cell (WBC) count and mean platelet volume (MPV) in all of them. Results: Following plateletpheresis a significant decrease in pre-and post-donation Hb (g/dL) (14.8 ± 1.097 Vs 14.5 ± 1.4; p=0.002); haematocrit (%) (43.29 ± 6.62 Vs 41.64 ± 4.96; p=0.045); platelet count ( 10 9 /L) (280.34 ± 54.55 Vs 175.58 ± 44.56; p< 0.001); WBC count ( 10 3 /μL) (8.28 ± 1.88 Vs 6.95 ± 1.76; p< 0.001); and PDW (fL) (15.96 ± 1.38 Vs 4.96 ± 0.67; p=0.053) and a slight rise in MPV (fL) (8.61 ± 0.77 Vs 8.72 ± 0.83; p=0.067) were observed. However, none of them developed clinical manifestation of anaemia or thrombocytopenia. Conclusions: Close monitoring and follow-up for these donors is indicated to prevent unfavourable events caused by these changes. DS. Changes in pre-and post-donation haematological parameters in plateletpheresis donors. J Clin Sci Res 2014;3:85-9. DOI: http://dx.