Although interleukin 13 (IL‐13) is an important mediator of asthma and allergic diseases, the molecular mechanisms regulating IL‐13 gene expression are not well understood. This study was designed to define the molecular mechanisms governing IL‐13 gene expression in T cells. IL‐13 expression was examined in human peripheral blood T cells and in the EL‐4 T‐cell line by enzyme‐linked immunosorbent assay and reverse‐transcription polymerase chain reaction. An IL‐13 promoter deletion analysis was performed using luciferase‐based reporter plasmids transiently transfected into EL‐4 cells by electroporation. DNA binding factors were investigated using electrophoretic mobility shift assays. In contrast to IL‐4 expression, which required concomitant activation of calcium‐ and protein kinase C‐ (PKC‐) dependent signalling pathways, PKC activation alone was sufficient for IL‐13 protein secretion in mitogen‐primed (but not resting) peripheral blood T cells, and for IL‐13 mRNA expression and promoter activity in EL‐4 T cells. Promoter deletion analysis localized a phorbol 12‐myristate 13‐acetate (PMA) ‐sensitive element to a proximal promoter region between − 109 and − 79 base pairs upstream from the IL‐13 transcription start site. This promoter region supported the binding of both constitutive and PMA‐inducible nuclear factors in gel shift assays.