Diarrhea caused by Cryptosporidium is most commonly seen in patients with HIV or AIDS or other immunocompromised conditions like diabetes mellitus, or patients on a high dose of steroids or immunosuppressants. The organism is a parasite that infects gastrointestinal epithelium, producing potential life-threatening diarrhea in people with AIDS but usually self-limiting diarrhea in immunocompetent hosts. Here in, we present an interesting case of persistent diarrhea caused by Cryptosporidium in an immunocompetent adult requiring treatment with nitazoxanide.