The French Phytoplankton and Phycotoxins monitoring network (REPHY) recently found positive or dubious negative shellfish samples using lipophilic toxins mouse bioassay. These samples were analyzed by liquid chromatography (LC) in combination with mass spectrometry (MS) to detect the following toxins: okadaic acid (OA), dinophysistoxins (DTXs), pectenotoxins (PTXs), azaspiracids (AZAs), yessotoxins (YTXs), spirolides (SPXs) and gymnodimines (GYMs). Over the 2006-2007 period, chemical analyses revealed various lipophilic toxin profiles according to shellfish sampling locations. In addition to OA and/or PTX-2 and their derivatives, several other compounds were found for the first time in France: (1) during the summer of 2006, AZA-1 and AZA-2 in Queen scallops (Aequipecten opercularis) from Northern Brittany; (2) during the summer of 2007, YTX and its major metabolites (45-hydroxy-YTX, homo-YTX, carboxy-YTX) in shellfish from the Mediterranean coast. Regarding YTX-group, the toxin profiles evolution in mussels during summer showed that: (i) the carboxy-YTX depuration rate was much slower than the YTX and 45-hydroxy-YTX ones; (ii) the homo-YTX concentration, which was initially very weak, increased significantly during the last deputation phase, which seems to reveal a YTX-group high metabolisation level in mussels. This paper reports for the first time on AZA and YTX-groups detection in French shellfish. (C) 2008 Elsevier Ltd. All rights reserved.