The red seaweed dulse (Palmaria palmata) is one of the more popular seaweed species for human consumption in the Western world. With a documented historical use up to present days in Ireland, Brittany (France), Iceland, Maine (USA), and Nova Scotia (Canada), it has remained a snack, a food supplement, and an ingredient in various dishes. The trend towards more healthy and basic foodstuffs, together with an increasing interest among chefs for the seaweed cuisine, has posed the need for more quantitative knowledge about the chemical composition of dulse of relevance for human consumption. Here, we report on data for amino acid composition, fatty acid profile, vitamin K, iodine, kainic acid, inorganic arsenic, as well as for various heavy metals in samples from Denmark, Iceland, and Maine.