A molecular phylogenetic study of the river kingfishers published in 2007 found that the genera as then defined did not form monophyletic groups.

Alcedo species typically have metallic blue upperparts and head, and orange or white underparts.

[6] The small kingfishers that make up the rest of the family have blue or orange upperparts and white or buff underparts, and show little sexual variation.

No members of this family are found in the Americas, although the American green kingfishers are believed to have derived from alcedinid stock.

The Alcedo kingfishers are usually closely associated with fresh water, often in open habitats although some are primarily forest birds.

[8] Egg laying is staggered at one-day intervals so that if food is short only the older larger nestlings get fed.

[10] The small Ceyx and Ispidina species feed mainly on insects and spiders, but also take tadpoles, frogs and mayfly nymphs from puddles.

The Alcedo kingfishers are typically fish-eaters with black bills, but will also take aquatic invertebrates, spiders and lizards.