The purpose of this study was to investigate possible alterations in acid-base balance parameters and the coagulation profile in neonatal diarrheic calves. Twenty neonatal diarrheic and 20 clinically healthy neonatal calves aged between 1 week to 10 days were used. All blood samples were taken on the third day from the onset of diarrhea symptom. Venous blood samples were collected from each animal to determine platelet numbers, pH, pCO2, pO2, HCO(3-), BE, O2SAT, ctCO2 and electrolytes (K+, Na+ and Cl(-)). Plasma samples were collected from each animal for the measurement of prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), the concentrations of fibrinogen, D-dimer and the activity of antithrombin III (AT III). Blood pH (7.19), BE (-10.6 mmol/l), HCO3(-) (25.15 mmol/l), pO2 (3.33 kPa), O2SAT (24.12 %) were significantly lower and serum concentration of K+ (6.55 mmol/l) was significantly higher in diarrheic calves. These changes indicate the state of uncompensated metabolic acidosis with accompanying hyperkalemia. TT (32.05s) and APTT (39.9s) values were more prolonged in calves with diarrhea than in the control group. D-dimer (587.25 microg/l) concentrations were significantly increased while a visible drop in AT III (103.75%) activity and platelets counts (598 x10(9)/l) were observed in diarrheic group of calves. The results suggest that a consumptive type of disseminated intravascular coagulation (DIC) developed in diarrheic calves.