Ecological scientists in many countries routinely monitor their coastal waters for potential harmful algae in order to prevent harvesting of contaminated sea food, but this is not the cause for Iraq The present work is the first attempt to recognize the potential harmful algae in the coastal waters of Iraq. Samples were collected from different locations along Shatt Al-Arab estuary and coastal line of Iraq for two years from February 2013 to December 2014. The water temperature during sampling period ranging between (26.67?-31.84?) at all stations. The salinity were fluctuated between (15-45.7) %, N:P ratio were (3-26). In this study (16) species of potential harmful algae were recorded during this period some of these are toxic. The dominate species were Ceratium furca, Dinophysis caudata, Dinophysis mile, Noctiluca scintillans, Prorocentrum micans, Protoperidinium divergens, P. despressum. Four species were recorded for first time in Iraqi costal waters including C. declinatum, Dinophysis acuminatum, Protoperidinium steini and P. subinerme.