In recent decades, plastic pollution has become a global critical environmental issue as a result of the imbalance between the production rate of plastics and a country’s ability to properly manage the waste. As a result, huge amounts of plastic waste have accumulated in the environment causing plastic pollution, especially in the Mediterranean Sea, which is one of the most polluted places in the world. Plastic fragments, particularly microplastics (MPs), enter the marine environment via primary and secondary sources of pollution, i.e., plastics originally manufactured in micro sizes for household products, cosmetics, and paints, or plastics fragmented by physical and biological processes. The toxicity of MPs is related mainly to their physical and chemical characteristics. In terms of size, MPs are less than 5 mm down to nanosized particles, with shapes varying from spheres to fibers, films, and hard fragments. Chemically, MPs are composed of hundreds of polymers and varying types of plasticizers. The significant risk of MPs is originated mainly from their bioavailability via marine food-web and associated impacts on the functionality and wellbeing of marine organisms. MPs adsorb contaminants from the environment, such as; polycyclic aromatic hydrocarbons and metals. These contaminants eventually are transported to the surrounding environments and marine organisms and cause particular concerns for human exposure. Once MPs accumulate in the organisms, they may cause physical blocking of the digestive tracts, physiological disturbances, osmotic regulation, reproductive abnormalities, biochemical alterations, etc., which subsequently cause potential risks for human health. The choice of an adequate analytical protocol for MPs extraction is of great importance. The chemical analysis must be reliable, economical, and not require complex purification procedures. Several tools have been utilized to study MPs, including visual and instrumental techniques. Quantification of MPs by counting plastic-like particles is highly subjected to human error and can create miss interpretation of MPs' abundance and impact. Although protocols for visual sorting of environmental MPs exist employing it as a stand-alone technique would not be the most suitable approach, but it is a crucial step to narrow down the number of particles examined using subsequent analytical techniques. ATR-FTIR coupled with microscopy is a commonly used technique for the characterization of MPs. The thermal analysis provides an effective protocol to study MPs in environmental samples. DSC measurements allow for the study of semi-crystalline thermoplastics in different matrices and thus provide reliable data on MPs in several potential sources. While DSC represents the physical state change of thermoplastics in the temperature range from room temperature to 350 ºC, several overlapping peaks would exist beyond 350 ºC due to the pyrolytic decomposition of plastic polymers. Moreover, the TGA provides information in the temperature range 350 – 500 ºC, since the TGA curve shows a mass loss step, and the peak temperature (decomposition temperature of plastics) of the calculated derivative of the TGA curve (DTG), is designated around 500 ºC. The presentation will show our recent studies about the plastic particles accumulated in commercially fish species and the beaches of Alexandria coast, Mediterranean Sea, Egypt.