The current study aimed to detect the prevalence of Cryptosporidium parvum in immunocompromised patients of Wasit Province, Iraq. A total of 80 stool collected from immunocompromised patients during the period 1st of October to the end of December, 2021 from both genders who attended the hospital and health centers at Wasit province. Stool samples were investigated by modified acid-fast stain and Nested PCR methods. Modified Ziehl-Neelsen technique revealed 32 (40%) positive cases for Cryptosporidium oocysts, of 50 males and 30 females, and the higher infection appeared in age group (1-10) years old with highly significant relationship between the genders and different age groups of infection. The prevalence of Cryptosporidium parvum was 48 (60 %) using nested PCR in comparison with MZN method. It is concluded that Cryptosporidium parvum infection found to be endemic in Wasit Province for the first time and the nested PCR was the most reliable technique for its diagnosis.