Plastic debris or microplastics ranging between 1 and 5000 μm is currently a global issue that has drawn the attention of the scientific community and policymakers. A recent report reckons about 51 trillion microplastic particles float in surface waters worldwide. Microplastics coupled with additive compounds such as plasticizers, stabilizers, and pigments are known to be hazardous for humans and other organisms. In that context, the current study attempts to understand microplastics in the coastal water samples collected from the southwestern coast /Malabar coast of Kerala at 40 sites covering five districts, including Kollam, Alappuzha, Ernakulam, Thrissur, Malappuram, and Kozhikode. The study focused on the size ranges of microplastics (0.1–5 mm), colour and the functional group identified through Fourier-transform infrared spectroscopy (FTIR). The study confirms the presence of polypropylene (PP), polyamide, nylon, Polyvinylpyrrolidone and the influences of physico-chemical parameters of water.