The Malaysian construction industry is experiencing rapid growth, driven by increasing demand for residential homes, commercial buildings, and business premises. Lightweight concrete, now an essential building material, has prompted further research into its development. The objective of this study is to identify suitable materials and optimal mixing ratios for producing lightweight concrete blocks using industrial waste products. Specifically, Expanded Polystyrene (EPS) and pressmud, a by-product of the sugar industry, were incorporated. In this study, a 1:2 mixing ratio was used to produce blocks measuring 500mm x 200mm x 100mm, incorporating EPS and pressmud. Research indicates that EPS is an effective lightweight material in concrete mixtures due to its favorable properties. Pressmud was also found to be a valuable additive, as its characteristics are similar to sand. Additionally, its moisture content enables a reduction in the required amount of both sand and water in the mix. The most favorable outcome was observed in the third sample, which used a mixing ratio of 8:16:6. The study successfully achieved its objectives, resulting in the production of lightweight concrete blocks. This sustainable approach not only offers an innovative building material but also provides a solution for the sugar industry by utilizing pressmud, reducing industrial waste and supporting environmental sustainability.