Since chemotherapy started in 1940s, chemosensitivity testing has been both a very attractive field and one fraught with potential pitfalls. Many methods were developed and brought initial promises, yet later ending in disappointment and were eliminated. For example, in the 1970s clonogenic assay was generally believed to be the best testing method for predicting clinical outcome. However, technical problems including low evaluation rate limited its use. Currently, MTT, ATP, DISC and Kern’s assay hold better promises. Since the 90s, the study of molecular biology has been progressing rapidly. It accelerated the understanding of molecular mechanisms of drug response. Numerous papers were published, but only few techniques can be applied in clinical practice. This review summarizes the controversies and current progress of chemosensitivity assays based on available online information, and makes a suggestion about their future routine practice.