The bloom of Noctiluca miliaris (a dinoflagellate) which appears in the form of a green tide was studied from 2003-2011. This bloom covered a large area of the Arabian Sea from the west coast of India to the coast of Oman. The bloom was easily identified by OCM I and OCM II images (as well as SeaWiFs images) and had been sampled by Indian research vessels like the Sagar Kanya and the Sagar Sampada. The bloom persisted for almost 4 months (January-April) and its peak levels were seen from 15 Jan-15 Feb. N. miliaris is characterized by the presence of the symbiont Pedimonas noctilucae. This organism shows a predominantly green colouration due to the presence of high chlorophyll b along with chlorophyll a. Time series of OCM I and OCM II images were used to establish the onset and demise of this bloom. Simultaneously samples were taken during cruises and these were analyzed for pigments and other associated biological parameters. The bloom period corresponded with the NE monsoon of the region. Weekly images of OCM-I were used to establish the growth and demise of the N. miliaris. The data collected along the same lines prior to the N. miliaris bloom as well as in post bloom conditions will be presented and discussed. A total of eight cruises were undertaken during the years from 2003-2011 in the Arabian Sea and both OCM I and OCM II data has been used.