Owing, on the one hand, to the constant increase in the %s of nickel sensitization in the majority of allergy departments of dermatology and, on the other, to the fact that sensitization to nickel is almost always through contact with jewellery and imitation jewellery, an update was carried out on the metal alloys principally used in the manufacture of such jewellery (earrings, bracelets, necklaces, rings, watch straps, etc.) The conclusions of this review demonstrate that nickel is irreplaceable in the majority of the alloys, because of its excellent technical properties and low price and, as a result, the % of sensitizations to this allergen will not only maintain their present high level but will probably increase in the future.