Liquid-liquid flow through compact geometries has been gaining importance in recent time. It is encountered in the pharmaceutical industry and fine chemicals industry where high throughput separation is required. The extraction and kinetic process for two-phase systems can be enhanced by working in micro dimensions due to the higher interfacial area. Liquid-liquid flow in miniature channels varies from macro channels due to the difference of forces that act along with the interface like the effect of inertia and gravity is less prominent as compared to surface tension forces. The current work presents a comprehensive review of liquid-liquid flow particularly in micro dimensions and focuses on flow visualization studies, mass transfer, and pressure drop investigations. The main uniqueness in this review work is that a comprehensive study dealing with transport processes in a microdomain is reported in a detailed fashion with all important findings which can be a base for the starting of experimental investigations in these micro dimensions. Micro dimensions are current techniques for process intensification which plays a very important role in any process industries. A detailed critical review has been included in the review which suggests that micro dimensions serve an effective tool for process intensification.