[1] Although mostly Neotropical in distribution, the family is also represented both in the Nearctic, Palearctic, Australasian (Dicallaneura), Afrotropic (Afriodinia, Saribia), and Indomalayan realms.

They may resemble butterflies in other groups, some are similar to Satyrinae, some are bright yellow reminiscent of Coliadinae and others (examples Barbicornis, Rhetus arcius, Helicopis, Chorinea) have tails as do Papilionidae.

[3] The golden or silvery metallic spots on the wings in many species of the Americas gave them the English common name "metalmarks".

[4] Mimicry causes often closely related species to have completely different wing patterns, for example the genus Thisbe.

In almost all Riodinidae, the coxae of the front legs are extended on males jutting out over the trochanter (only hinted at in Styx infernalis and Corrachia leucoplaga).

If there are similar projections in Lycaenidae (in genera Curetis, Feniseca and Poritia), they are built differently in detail and may be, for example, dorsally convex.

[8] In addition, almost all Riodinidae in contrast to the Lycaenidae have a humeral vein in the hindwings and the costa is thickened (exceptions in the subfamily Hamearinae).

[9] Riodinidae is currently treated as a distinct family within the superfamily Papilionoidea, but in the past they were held to be the subfamily Riodininae of the Lycaenidae.

Kristensen et al.[12] accepted the updating of the manual in 2007 raising the classification to family rank at least on a provisional basis.

Molecular phylogenetics (based on homologous DNA sequences) establishes a sister group relationship between the Riodinidae and the Lycaenidae accepted almost unanimously.

Species occur in a variety of habitats, but have a unique distribution focus in the tropical rain forests of South America.

However, gregarious caterpillars are found within the Euselasiinae (Euselasia), Riodinini (Melanis) and Emesini (Emesis), with some species demonstrating processionary behaviours.

Available evidence from Euselasia and Hades suggests the gregarious trait may be widespread among members of the subfamily Euselasiinae.

Many Riodinidae larvae have so-called "tentacle nectary organs" on the eighth segment of the abdomen that secrete a fluid which is eaten by ants.

[23] The larvae feed on plants of the families Araceae, Asteraceae, Bromeliaceae, Bombacaceae, Cecropiaceae, Clusiaceae, Dilleniaceae, Euphorbiaceae, Fabaceae, Lecythidaceae, Loranthaceae, Malpighiaceae, Marantaceae, Melastomataceae, Myrtaceae, Orchidaceae, Rubiaceae, Sapindaceae, Zingiberaceae as well as bryophytes and lichens.