Domoic　acid　(DA),　a　neurotoxic　amino　acid　produced　by　some　strains　of　phytoplankton,　is　responsible　for　the　human　toxic　syndrome　amnesic　shellfish　poisoning.　This　exocitotoxin　results　in　neuronal　degeneration　and　necrosis　in　specific　regions　of　the　hippocampus.　Because　DA　accumulates　mostly　in　shellfish,　causing　outbreaks　in　different　countries,　screening　for　DA　has　been　carried　out　with　various　assays.　Although　bioassays　and　immunoassays　have　been　developed,　several　liquid　chromatographic　methods　for　the　determination　of　DA　in　different　matrices　such　as　shellfish,　algae,　or　seawater　have　been　reported.　Additionally,　other　alternative　methods　such　as　capillary　electrophoresis　and　capillary　electrochromatography　have　been　described.　This　paper　summaries　the　toxicology,　the　chemistry,　and　the　developed　determination　methods　of　DA.