Immunocompromised patients present with altered pattern, progression and clinical manifestations of parasitic infections. Patients with impaired cell mediated immunity are susceptible to infection with Toxoplasma gondii, Cryptosporidium, Leishmania, Strongyloides and Microspora. Defects in humoral immunity make the patient susceptible to infection by parasites like Gairdia lamblia and Cryptosporidium. The immunocompromised patients are at risk of developing various parasitic infections. In this chapter illustrative photomicrographs of 10 cases of various parasitic infections involving wide variety of tissues and organs including rare sites like brain under diverse clinical settings have been described. Descriptive legends of each case include the clinical presentation, radiological findings, laboratory and serological work up and the findings of stool examination wherever indicated have been provided. Relevant references to the text have been provided.