Many researchers have pointed out that the intake of omega-3 and -6 fatty acids is beneficial to animal health and reproductive capacity, but the effect of fatty acids on the histomorphology of ram testes is still unknown. The aim of this study was to investigate the effect of linseed oil containing polyunsaturated fatty acids on the morphology and histomorphometric characteristics of ram testis and epididymis. Testes of 12 Lithuanian local coarse wool rams were investigated histomorphologically and histomorphometrically in the present work. The rams were divided into two groups, an experimental group and a control group following, the principle of analogues – the same origin, age, weight, and condition score. The experimental group (n = 6) received 2% linseed oil sediments while the control group (n = 6) received 1.2% sunflower oil for 9 months. The diameter of testicular tubules and the height of the germinal epithelium, the spermatogenic index and the number of Leydig cells were higher in the experimental group than those in the control group. In addition, the number of degenerated tubules was not significantly lower in the group that received 2% linseed oil sediments. Still, the height of the epididymal epithelium was lower than that in the control group....