Present study intended to estimate prevalence of Cryptosporidium infection in dairy calves of different ages (1-3 months). It aimed to determine relation between incidence rate and the age of calves. A total of 717 fecal samples Friesian and buffalo calves were selected from Minufiya governorate. Samples were examined using the safranin staining method. Highest prevalence of Cryptosporidium (56.32%) was observed in one-week old calves. Age specific variation for occurrence of parasites was not significantly different for Cryptosporidium. Highest rate of infection by Cryptosporidium was recorded in summer (46.39%) then spring (45.65%), autumn (24.18%), winter (16.33%). Highest rate of infection by Cryptosporidium was recorded in August (60.00%), Mar (54.56%) and Apr (50.00%). While in December, incidence was (23.08%). Moreover, statistical analysis showed that cryptosporidium oocyst shedding among diarrheic calves was significantly higher (p < 0.001) than that of non-diarrheic calves. While in buffalo calves, highest prevalence of Cryptosporidium (34.07%) was observed in one week-old calves. Age specific variation of parasites was statistically not significantly different for Cryptosporidium. Highest rate of infection by Cryptosporidium was recorded in summer (34.19%) then spring (18.18%), autumn (14.29%), winter (8.70%). Highest rate of infection by Cryptosporidium was recorded in August (57.14%), May (40%) and June (31.68%). While in December, incidence was 10.00%. Moreover, statistical analysis showed that cryptosporidium oocyst shedding among diarrheic calves was significantly higher (p < 0.001) than that of non-diarrheic calves. |