This study reports potential causes of diarrhea in neonatal calves, leading to calf mortality, from the selected population of the three Provinces of Turkey. A total of 300 fecal samples were collected purposively from diarrheic neonatal calves distributed to the three age groups (1–14 days, 15–29 days, and 30–90 days), from Konya, Karaman, and Aksaray Provinces of Turkey. The fecal specimens were examined for the existence of Cryptosporidium spp., rotavirus, coronavirus, and Escherichia coli by commercially available capture direct enzyme linked immunosorbent assay (ELISA) kit. The oocysts and coproantigens of Cryptosporidium were identified in 109 (36.3%) and 156 (52%) of the 300 calves, respectively. While, rotavirus, E. coli and coronavirus antigens were detected (P<0.05) in 57 (19%), 17 (5.6%) and 6 (2%) calves, respectively. Mixed infection of the study pathogens has also been found in this report. These results provide a baseline information on the frequent causes of neonatal calf diarrhea in the studied Provinces which can be used to develop a prophylaxis plan.