The work reviews the possibility of using thromboelastogram to assess the coagulation potential in horses. The experiment engaged ten clinically healthy mares aged from one to five years and five newborn foals up to ten days of Russian trotting breed. The thromboelastogram was recorded in citrated blood by means of a two-channel computerized Coagulation Analyzer (TEG® 5000 - Hemoscope, USA) and applied diagnostic program. Such parameters as R (min), K (min), Ang (°), MA (mm) were taken into consideration; no significant difference was found in parameters between mares and foals. R (min) and K (min) were higher in horses (13.55 ± 2.11 min and 4.6 ± 0.91 min, respectively) than in foals (12.77 ± 0.41 min and 3, 65 ± 0.34 min, respectively). Ang (°) was lower in horses compared to foals (46.41 ± 5.89 ° and 52.14 ± 3.58 °, respectively). MA (mm) was at the same level in animals of both groups and amounted to 57.28 ± 3.04 mm in horses and 57.77 ± 2.59 mm in foals. The work presents reference coagulation intervals in adult horses and foals, but when interpreting of individual results, the effect of hematocrit, platelet count and fibrinogen concentration must be taken into account.