Saphenous vein graft disease (SVGD) after by-pass surgery is an important cause of morbidity and mortality for patients with coronary artery disease. Comprehensive evaluation of biochemical and hematological parameters associated with this problem is limited. Plateletcrit (PCT) provides complete information on total platelet mass, but it has not been previously studied. In this study, we examined the relationship between SVGD and platelet parameters such as PCT, mean platelet volume, platelet count, and platelet distribution.We retrospectively analyzed 14,398 patients who underwent coronary angiography between February 2006 and August 2012. Records from 893 patients with previous coronary artery by-pass graft operation were re-evaluated. A total of 251 cases were divided into two groups (127 patients receiving a saphenous vein graft; 124 patients diagnosed with SVGD) and hematological and biochemical parameters were compared.There were no significant differences in clinical characteristics between the two groups except that the SVGD group had a higher median time from surgery to coronary angiography than the patent saphenous vein graft group [7 years (2-16) vs. 5 years (2-15), p < 0.001]. The SVGD groups also had significantly higher median PCT, mean platelet volume, platelet count, uric acid level, and red blood cell distribution width. The cut-off value for PCT was found to be 0.188 for predicting SVGD, with an 80.65 % sensitivity and 81.1 % specificity.Plateletcrit has an important predictive value for SVGD, and it could be used as a marker for anti-platelet therapy to prevent graft atherosclerosis in patients undergoing by-pass surgery.