Chemical biology provides an alternative way to identify genes involved in a particular biological process. It has the potential to overcome issues such as redundancy or lethality often found in genetic approaches, since the chemical compounds can simultaneously target all homologous proteins that function at the same step, and chemicals can be applied conditionally. Even with a variety of genetic approaches, the molecular mechanisms of plant hypersensitive cell death that occurs during disease resistance responses remain unclear. Therefore, application of chemical biology should provide new insights into this phenomenon. Here we describe a high-throughput chemical screening procedure to detect hypersensitive cell death quantitatively, using a suspension cell culture of Arabidopsis thaliana and a well-studied avirulent bacterial pathogen, Pseudomonas syringae pv. tomato DC3000 avrRpm1.