Azadinium spinosum, a small dinoflagellate has recently been discovered and identified as the primary producer of azaspiracid-1 (AZA) and -2. Since AZA poisoning has been reported following consumption of contaminated shellfish it is important to have these toxins available for toxicological studies, and a sustainable production of AZAs as calibrants in monitoring programs without having to rely on natural events. In order to address this concern, continuous pilot scale cultures were carried out to evaluate the feasibility of AZA production from A. spinosum. Algae were cultured using two 100 L chemostats in series (R1 and R2), with agitation and pH control. Four different dilution rates were tested (0.15, 0.2, 0.25 and 0.3 day−1) to evaluate chemostat bioreactors in terms of cell and toxin productivity. Algae were collected in a 300 L transparent cylindro-conical tank and harvested with a tangential flow filtration device. Subsequently, toxins were extracted from the algal retentate and separately from the permeate using solid phase adsorption procedures. The cell concentration at steady state remained stable using different dilution rates (190,000 and 210,000 cells · mL−1 in R1 and R2 respectively). However, the AZA cell quota decreased as the dilution rate increased, consequently an optimum production was obtained at 0.25 day−1 under the studied conditions. After filtration, 50–70 % of the toxin was contained in the retentate and 30–50 % was released into the permeate. After optimization, the procedures for solid phase extraction of toxins from the retentate and permeate allowed for the recovery of 80 ± 5 % of original toxins produced. This work demonstrated the feasibility of producing AZAs from A. spinosum produced in a bioreactor for purification and production of certified standards.