In both developing and developed countries, intestinal protozoa cause infections. Diarrhoea is a manifestation of parasitic infections. Most of these occur in developing countries, causing around 3-4 million deaths each year. One of HIV's most common symptoms is diarrhoea. Opportunistic and non-opportunistic organisms are the etiological agents. Opportunistic agents cause diarrhoea that is severe, persistent or chronic. A typical symptom of persistent diarrhoea in HIV/AIDS patients is the duration of diarrhoea for more than 4 weeks. Hence, this article discusses some literature on parasitic diarrhoea in patients with HIV/AIDS. It has been estimated that 4 billion cases of acute diarrhoea occur globally every year.In the world's developing nations, the economic effects of diarrhoea are more demanding. Giardia lamblia, Entamoeba histolytica Cryptosporidium parvum, Cystoisospora belli, Cyclospora cayetanensis, Blastocystis hominis and Microsporidium spp are the protozoan parasites involved in causing diarrhoea in patients with HIV/AIDS (Tables 1 and 3). HIV weakens the immune system and can contribute to opportunistic infections (OIs) that can cause several symptoms. For HIV/AIDS patients, identifying the cause of diarrhoea will help determine the best treatments for long-term management and better quality of life. Untreated diarrhoea is highly dangerous, dehydration or other life-threatening complications can result. With home remedies and changes in diets, diarrhoea may be handled.