ISWA Lebanon hosted the President of ISWA (International Solid Waste Association), Mr. Antonis Mavropoulos, to a round table discussion on “Marine Litter in Mediterranean Sea – A Challenge turning to a serious threat”. The discussion highlighted that Marine Litter stretches beyond the visible floating litter to the micro-plastics and highlighted various major sources of Marine Litter in the World and in the Mediterranean. The primary Micro plastics have been estimated to be in the range of 32,000 to 236,000 metric tonnes in oceans while macro plastics emitted directly to oceans from coastal zones are in the range of 4.8 to 12.7 million tonnes per year. As for the Mediterranean Sea, sanitary waste and coastal tourism contribute to more than 50% of its Marine Litter. The discussions also highlighted the criticality of the Mediterranean Sea since its water changes once every one thousand years. The discussions also highlighted the impact of Marine Litter on biodiversity, on various marine species, on humans, and on the ecosystem. Finally, required actions, studies, and measurements to face Marine Litter challenges were pointed out.