The rizosphere is the most biologically active volume of soil around plants roots that is influenced by their activities. Due to the influence of roots, the rhizosphere differs from bulk soil significantly in its chemical, physical, and biological characteristics. The rhizosphere represents an extremely complex and dynamic environment where numerous interactions occur simultaneously between roots, solutes, organic compounds, minerals, gases and (micro)organisms. These processes affect root growth and development, efficiency of nutrients and water uptake, and consequently the productivity of plants. Agricultural production heavily depends on understanding the rhizosphere processes. Rhizosphere research is a challenging task in terms of experimental design and methodology because of complexity of these processes occurring at a micro-scale. In particular, access to study these processes and phenomena in situ is limited as they occurring below-ground. Despite tremendous progress in method development in the past decades, finding suitable experimental setups to investigate rizosphere processes still represents a major challenge. This review paper critically assesses available literature and discusses approaches and methods of rhizosphere research, with emphasis on visualization techniques of rhizosphere processes. In the first section access to rhizosphere and description of its properties is presented, covering methods for sampling rhizosphere soil and collection of root exudates and rhizosphere soil solution. Various experimental systems suitable for use under field and laboratory conditions are discussed, with an overview of main advantages and limitations of a certain method. Tracing rhizosphere processes with isotopes is the topic of the second section, while the third section is devoted to visualization techniques of rhizosphere processes. They include a presentation of cutting-edge methods of chemical, non-invasive, isotope and microbial imaging. Currently, the understanding of rhizosphere processes is incomplete, emphasising the need for using combinatorial approaches that have great potential to unravel complex rhizosphere processes.