Soursop is the fruit of Annona muricata, a broadleaf, flowering, evergreen tree native to Mexico, Cuba, Central America, the Caribbean islands of Santo Domingo and Puerto Rico, and northern South America, primarily Colombia, Brazil, Peru, Ecuador, Venezuela. Soursop is also produced in some parts of Africa, especially in Eastern Nigeria, Southeast Asia and the Pacific. It is in the same genus as the chirimoya and the same family as the pawpaw.

The soursop is adapted to areas of high humidity and relatively warm winters; temperatures below 5 °C (41 °F) will cause damage to leaves and small branches and temperatures below 3°C (37 °F) can be fatal. The fruit becomes dry and is no longer good for concentrate.

Other common names include: Mãng cầu Xiêm (Vietnamese), Coração de Boi (Mozambique), Evo (Ewe, Volta Region, Ghana), Ekitafeeli (Uganda), Mtomoko (Swahili), Aluguntugui (Ga, Greater Accra Region, Ghana), guanábana (Spanish), graviola (Brazilian Portuguese, pronounced: [ɡɾɐviˈɔlɐ]), anona (European Portuguese), graviolo (Esperanto), corossol (French), kowosòl (Haitian Creole), කටු අනෝදා (Katu Anoda) (Sinhalese), sorsaka (Papiamento), adunu (Acholi), Brazilian pawpaw, guyabano, guanavana, toge-banreisi, durian benggala, durian belanda, nangka blanda, ทุเรียนเทศ [turi:jen te:d] (Thai), sirsak (Indonesia), zuurzak (Dutch), tomoko (Kiswahili), and nangka londa. In Tamil, Malayalam, it is called Mullatha, literally thorny custard apple. The other lesser-known Indian names are shul-Ram-fal and Lakshman Phala, and in Harar (Ethiopia) in Harari language known for centuries as Amba Shoukh (Thorny Mango or Thorny Fruit).

The flavour has been described as a combination of strawberry and pineapple, with sour citrus flavour notes contrasting with an underlying creamy flavour reminiscent of coconut or banana. Soursop is widely promoted (sometimes as "graviola") as an alternative cancer treatment. There is, however, no medical evidence that it is effective.

By whatever name, this tropical evergreen tree produces a fruit with white flesh, many large seeds and an extremely sweet, slightly acidic flavor. Because it is difficult to eat, its pulp is commonly made into juice. Not only the fruit but also other parts of this plant — the leaves, stem, bark, roots, and seeds — have a long history of medicinal use in the Americas. Graviola is used as a natural remedy for infections, fever, digestive problems and high blood pressure [source: Cassileth]. Researchers have documented many other traditional uses among the indigenous people of the Andes, the Amazon and the Caribbean [source: Taylor]. Recently, scientists have begun to explore the potential of the bioactive chemicals in graviola leaves, stems and seeds, called annonaceous acetogenins. These acetogenins appear to have powerful anti-tumor and anti-cancer qualities. Some test-tube studies have concluded that graviola compounds may be able to target and kill cancer cells, even drug-resistant ones, without interfering with healthy cells.