The genus Tricolia(Phasianellidae) in the Eastern Atlantic and Mediterranean is reviewed on the bases of radular morphology, shell characters and polychromatism.The taxa included within the T. pullus (L.) group are not clearly separable and are treated as geographical subspecies:T. pullus pullus (L.), T. pullus picta (da Costa), T. pullus azorica (Dautzenberg), T. pullus canarica Nordsieck. The case of T. tenuis (Michaud) is problematic since it is clearly separable from sympatric T. pullus pullus in most parts of the Mediterranean but transitional to T. pullus picta, towards the Atlantic.Other taxa are considered as having specific status since they are consistently separable when found in sympatric populations. These include T. speciosa (Muhlfeldt), T. miniata (Monterosato), T. tingitana n.sp., T. petiti (Craven), T. nordsiecki (Talavera) and T. algoidea (Pallary). The last two species are stated for the first time as belonging to the Phasianellidae. The genus Epheriella Pallary, based on T. algoidea, is synonymized with Tricolia.