The growing demand for highly priced marine ornamental species has contributed to the endangered status of coral reefs. A list of 128 of the most heavily traded marine ornamental decapod crustacean species is tabulated. The development of commercial culture techniques, the knowledge of the larval development, and the association with vertebrate and invertebrate organisms are presented for these species. Forty-nine of the species are caridean shrimp, with the Hippolytidae family alone accounting for 15. Anomuran and brachyuran crabs are the next most traded groups (32 and 27 species, respectively), with the pricey stenopodidean shrimp, Astacidea, and Palinura lobsters being represented by a considerably lower number of species (7, 7 and 6, respectively). The main bottlenecks impairing the commercial culture of ornamental shrimp and lobsters are their long larval development and poor survival rates. The main constraint for the development of culture techniques for hermit and brachyuran crabs is their low commercial value. The ecological impacts of harvesting ornamental species are still poorly studied. Nevertheless, the collection in considerable numbers of hermit and small majid crabs (e.g., Clibanarius and Mithraculus) from tidal areas, fish cleaning shrimp (e.g., Lysmata and Stenopus), and the crown-of-thorns sea star eaters Hymenocera, is likely to have serious impacts on the ecosystem. The cooperation between researchers working on larval biology, population dynamics, ecology, aquaculture, and fisheries is essential to properly manage the collection of marine ornamental decapods.