Multi-organs-on-a-chip are microfluidic devices with multiple organs integrated on a single device, made up of cells of desired tissue/organ, enabling communication between organs, simulating the physiological environment. These chips are physiologically more relevant and show enhanced predictability of the efficacy and toxicity of drugs. These devices offer flexibility, affordability, reproducibility, and can be applied for personalized and precision medicine. Various physiological mechanisms that could not be understood using in vitro and in vivo models can be realized using the multi-organs-on-chip devices. This chapter discusses the application of multiple organs-on-a-chip for disease modelling. The microfluidic devices for cancer and cancer metastasis, infectious diseases are discussed in detail in this chapter. The efficacy of drugs and their off-toxicity is also discussed and compared to the conventional in vivo model. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.