Plastic and polythene are useful innovations and are used for many products ranging from paper clips to spaceships due to their cost effectiveness, versatility, ease of production, and water resistant. However, the misuse and improper disposal of plastic and polythene create serious environmental, health, social, and financial issues. Thus, it is important to adhere to responsible disposal methods. The present study focused on the magnitude of usage, disposal methods, public awareness, and perception toward household polythene and plastic usage and disposal methods. A total of 150 respondents were selected using the cluster sampling technique in the Kuruwita Pradeshiya Sabha, Ratnapura, Sri Lanka. The data were collected through face‐to‐face and online interviews. The weights of the collected wastes were measured through a handheld digital scale. The findings of the study revealed that the majority of the respondents use polythene and plastic products and 83.33% of the respondents use these for their daily life due to the lack of alternatives and easy availability. The majority of the respondents mentioned the use of separate bags for shopping made out of eco‐friendly materials. Shopping in supermarkets has been a reason to increase the usage of polythene and plastic. HDPE, PET, and LDPE were the most commonly‐used plastics types and among which HDPE was the highest (24%) in the study area. Findings further revealed that the people with post‐graduate education used more polythene and plastic (19.8%) and the usage was higher (40.39%) in families in the non‐governmental sector. The participants with monthly income higher than 100,000 LKR used more polythene and plastic (28.84%) compare to others. The common way of disposing of was burning and participants had only a fair knowledge of banning, recycling, reusing, and controlling plastic waste. The study revealed the need for strict regulations and necessary actions to control the usage of polythene‐based products.