In this study, umbilical cord-derived neonatal tetanus in calves was identified in Turkey. Four calves with tetanus-specific history and clinical findings were used. Blood samples were taken before and after treatment, and clinical findings were recorded. A tetanus-specific treatment procedure was performed. However, the calves died from not responding to treatment. Pretreatment white blood cell, peripheral blood polymorphonuclear leukocyte, creatine kinase (CK), and lactate dehydrogenase (LDH) levels were determined to be high. Aspartate aminotransferase, alanine aminotransferase, CK, and LDH activities were found to increase after treatment compared to before treatment. Gram-positive terminal spore-forming bacilli were observed in bacterioscopic examination of the necrotic tissue and swab samples from the umbilical cord region. The umbilical cord region was determined to be infected in all calves. In histopathological examination, pyogranuloma formation was observed in the wound area, and in Gram staining agents morphologically concordant with Clostridium tetani in necrotic material were observed. Blood serum of the calves was inoculated into mice. All mice died within 2 days after the inoculation, showing tetanus-specific clinical findings. As a result, bacterioscopy and histopathology of the umbilical cord region may be useful for diagnosis in addition to clinical findings. Mice trials may be used in confirming the diagnosis.