The aims of this study were to determine the prevalence of Cryptosporidium spp in dairy cows in central Thailand and to investigate the genotype of Cryptosporidium spp in this population. A total of 200 fecal samples from dairy cows were collected and examined by the acid-fast staining technique and polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP). The prevalence of Cryptosporidium infection in dairy cows was 7% (95% CI 3.5-10.5) by acid-fast staining, and 15.5% (95% CI 10.5-20.5) by PCR-RFLP. This is the first report of genetic identification of the C. parvum bovine genotype in dairy cows in Thailand. PCR-RFLP analysis showed all positive samples were C. parvum (bovine genotype). C. andersoni was not found in this study. The only significant risk factor for Cryptosporidium infection in dairy cows was age. Calves less than 2 months old were more frequently infected by Cryptosporidium than others (OR 13.82, 95% CI 3.67-51.97, p = 0.001). Cattle may be a potential source of human cryptosporidiosis.