This study describes for the first time the cultivation of Cerastoderma edule on a commercial scale. A protocol to grow F2 generation cockles was developed, which led to fine-tuning experiments for broodstock conditioning and spat growth. Broodstock animals were conditioned with diets of Isochrysis galbana (T-Iso) or Tetraselmis suecica, whereas a third group was not fed. The best diet, T. suecica, induced 12 females out of 100 animals to spawn a total of 3 380 000 eggs. The non-fed group did not spawn. Cockle spat (4.9 ± 1.0 mm) grew best when given a mixed diet of C. muelleri, T-Iso and Sceletonema costatum, or a mixture of P. tricornutum and S. costatum at a concentration of 240 cells μl−1 day−1, resulting in a tripling of their wet weight after 14 days. The impact of density, burrowing substrate and food availability on cockle spat growth (41 days old, 5.6 ± 1.2 mm) was studied for 11 weeks. Best results were obtained by culturing spat at ad libitum food conditions at 500 ind m−2, resulting in an average growth rate of 168 μm day−1, an average final size of 19.0 ± 1.9 mm and a total final biomass of 1040 g m−2.