Many dinoflagellates species, especially of theAlexandriumgenus, produce a series of toxins with tremendous impacts on human and environmental health, and tourism economies.Alexandrium tamutumwas discovered for the first time in the Gulf of Naples, and it is not known to produce saxitoxins. However, a clone ofA. tamutumfrom the same Gulf showed copepod reproduction impairment and antiproliferative activity. In this study, the full transcriptome of the dinoflagellateA. tamutumis presented in both control and phosphate starvation conditions. RNA-seq approach was used for in silico identification of transcripts that can be involved in the synthesis of toxic compounds. Phosphate starvation was selected because it is known to induce toxin production for otherAlexandriumspp. Results showed the presence of three transcripts related to saxitoxin synthesis (sxtA, sxtG and sxtU), and others potentially related to the synthesis of additional toxic compounds (e.g., 44 transcripts annotated as "polyketide synthase"). These data suggest that even if thisA. tamutumclone does not produce saxitoxins, it has the potential to produce toxic metabolites, in line with the previously observed activity. These data give new insights into toxic microalgae, toxin production and their potential applications for the treatment of human pathologies.