In recent years, in vitro three-dimensional (3D) cell culture systems that better mimic in vivo physiology and tissue microenvironment have become important. It is used for the pre-clinical evaluation of the efficacy and safety profiles of new drug candidates developed especially for the treatment of various diseases including cancer. 3D cell culture techniques overcome the inadequacy of conventional two-dimensional (2D) cell culture models as they are much more informative than the 2D systems. And they can easily replace or reduce the number of in vivo studies which arise many ethical problems in the development of novel therapeutics. This review focuses on the organoid cultures which are 3D bioengineered cell culture systems that guide cell behavior and cell order to mimic in vivo tumor microenvironment.