Crustaceans play essential roles as food sources for global coastal communities, and their fisheries and aquaculture support the economic growth of many coastal countries. Thus, the understanding of diseases in crustaceans, especially those with high economic values, are important for their cure and prevention. Among other parasites that parasitise crustaceans, parasitic barnacles (Rhizocephala) are considered the most intriguing, both in terms of their unique life cycle and the detrimental changes they induced upon their hosts such as host sterilisation, moult inhibition (anecdysis), growth reduction, feminisation of male individuals, and behaviour alteration. In addition to discussing in detail the morphological, physiological and behavioural changes caused by rhizocephalan infestations, this review also shows that rhizocephalans are found in most economically important crustacean species around the world. Based on their reported adverse effects on their hosts, their potential implications on various aspects of crustacean aquaculture including broodstock selection, culture and fattening, soft-shell crab production and breeding programs are discussed. Although treatment or cure for rhizocephalan infestation has yet to be found, several recommendations are provided to enable accurate identification and handling of infected hosts and exposed aquaculture facilities in order to minimize losses and prevent parasite outbreaks.