A new HPLC/DAD (Diode Array Detector) method is proposed for the identification of some carotene isomers. The operating conditions adopted permit the resolution of alpha-carotene, all-trans-beta-carotene, 9-cis-beta-carotene, 13-cis-beta-carotene and 15-cis-beta-carotene. Moreover, the chromatographic conditions reported are simplified in respect of those reported up to now. The method is applied to the determination of carotenoids in a dried Dunaliella salina extract, but it could be also applied to other organic matrices such as eggs.