Aims: To determine the transcriptional responses of Trichophyton rubrum to the artificial substance, PH11B. Methods and Results: The broth microdilution assay for antifungal susceptibility testing of dermatophytes was used to measure the minimum inhibitory concentration (MIC) of PH11B. cDNA microarray technology and real-time RT-PCR were used to study the transcriptional responses of T. rubrum to PH11B. The MIC determined was 16 mu g ml(-1). The analysis of microarray data revealed that 787 genes were affected. Transcript levels from 476 genes increased at least two times, while 311 gene transcript levels decreased at least two times. Conclusions: PH11B has strong antifungal activity and the transcriptional response of T. rubrum to PH11B was determined. Significance and Impact of the Study: This microarray data set provides an analysis of gene expression of T. rubrum under PH11B treatment. The data provide an insight into the various metabolic processes altered or activated by PH11B. This study provided an insight into the action mode of the PH11B on T. rubrum.