Most atolls consist of a large, ring-shaped coral reef supporting numerous small islands. Islands average only one to two square kilometers in area, and lie between one and 1.5 meters above mean sea level. The highest island is situated at three meters above sea level. Maldives has no hills or rivers. Although some larger atolls are approximately fifty kilometers long from north to south, and thirty kilometers wide from east to west, no individual island is longer than eight kilometers.

Each atoll has approximately five to ten inhabited islands; the uninhabited islands of each atoll number approximately twenty to sixty. Several atolls, however, consist of one large, isolated island surrounded by a steep coral beach. The most notable example of this type of atoll is the large island of Fua Mulaku situated in the middle of the Equatorial Channel.

The tropical vegetation of Maldives comprises groves of breadfruit trees and coconut palms towering above dense scrub, shrubs, and flowers. The soil is sandy and highly alkaline, and a deficiency in nitrogen, potash, and iron severely limits agricultural potential. Ten percent of the land, or about 2,600 hectares, is cultivated with taro, bananas, coconuts, and other fruit. Only the lush island of Fua Mulaku produces fruits such as oranges and pineapples partly because the terrain of Fua Mulaku is higher than most other islands, leaving the groundwater less subject to seawater penetration. Freshwater floats in a layer, or "lens," above the seawater that permeates the limestone and coral sands of the islands. These lenses are shrinking rapidly on Male and on many islands where there are resorts catering to foreign tourists. Mango trees already have been reported dying on Male because of salt penetration. Most residents of the atolls depend on groundwater or rainwater for drinking purposes. Concerns over global warming and a possible long-term rise in sea level as a result of the melting of polar ice are important issues to the fragile balance between the people and the environment of Maldives in the 1990s.