ABSTRACT The purpose of this study was to evaluate the effects of three different forms (powder, pellet, and coated pellet) of red ginseng marc (RGM) and fermented red koji (FRK) feed additive on the blood parameters and fatty acid (FA) profiles of laying hens, after two months of dietary supplementation. A number of 240 40-week-old Hy-line Brown laying hens were randomly designated to four dietary treatments, each with six replicates of 10 hens each, in a completely randomized design. The control group was fed a basal diet, and the other three treatments groups were fed 1% RGM powder mixed with FRK, pellets of 1% RGM with FRK, and coated pellets of 1% RGM with FRK. The powder and coated pellet diets contained the lowest total cholesterol and glucose levels, respectively, whereas the coated pellet diet contained the highest HDL cholesterol level, compared to the basal diet of the control group. For FA profiles, significant differences (p<0.05) were observed among the groups with regard to the percentages of myristoleic acid, palmitoleic acid, margaric acid, margaroleic acid, stearic acid, oleic acid, a-linolenic acid, eicosenoic acid, and docosahexaenoic acid. Moreover, addition of different forms of the RGM and FRK blend to the hen’s diets showed an increase (p<0.05) in the relative percentages of unsaturated fatty acids (UFA) and the UFA: SFA ratio and a decrease (p<0.05) in the relative percentages of saturated fatty acids (SFA) in the egg yolk, compared to the control group. In conclusion, dietary coated pellets of RGM and FRK as a feed additive blend had a beneficial effect on serum cholesterol and FA profiles in laying hens.