In this study, it was aimed that to evaluate clinical, hematological and interleukin-8 (IL-8) parameters in neonatal calves with diarrhea. The animal material of the study consisted of 14 neonatal calves with diarrhea aged between 0-15 days and 7 healthy neonatal calves. Disease agents were determined from the fecal samples obtained from the calves using rapid diagnostic test kits. Neonatal calves were divided into 3 groups as Escherichia coli (E. coli), rotavirus and control. Blood samples were collected from the vena jugularis of the calves in to anticoagulated and non-anticoagulated tubes. Hematological and IL-8 analyses were performed. IL-8 level was determined using a commercial ELISA kit. Age, heart rate per minute (P), respiratory rate per minute (R), erythrocyte (RBC), hemoglobin (HGB) and hematocrit (HCT) levels of calves were not different between the groups (P>0.05). Rectal temperature (T), total leukocyte (WBC), lymphocyte (LYM), neutrophil (NEU) and IL-8 levels of calves with diarrhea were statistically different between the groups (P<0.05). NEU level and IL-8 level were measured highest in calves in E. coli group and then in rotavirus group. There was a significant positive correlation between IL-8 to WBC and NEU levels (P<0.05). In conclusion, in this study, significant increases in serum IL-8 levels due to intestinal damage were determined in calves with E. coli and rotavirus diarrhea. In addition, serum IL-8 levels were found to increase more (P<0.05) in bacterial E. coli diarrhea than viral rotavirus diarrhea.