Paracentrotus lividus gonads are gastronomic delicacies widely appreciated in Europe. Two commercially exploited populations of sea urchins were characterized, for the first time, in terms of gonad quality (market-related traits such as colour, texture and nutritional value) and safety (contaminants levels) to define the best season for harvesting this valuable resource. Spawning occurred between spring-summer, yet gonad index peaked only in one population during winter. In both populations, the strongest yellow colouration and highest gonad firmness, protein, lipid, polyunsaturated fatty acids and carotenoid contents as well as the lowest contents of mineral were registered in fall. Inorganic and organic contaminants levels were, in general, similar among sites and seasons, being found at trace levels in seawater and gonads, with low risk for consumers. For these populations, high-quality gonads can be harvested during fall, despite being safe for human consumption all year round.