AbstractA homogeneous and reproducible fluence rate delivery during clinical photodynamic therapy (PDT) plays a determinant role in preventing under‐ or overtreatment. The development of a flexible light source able to generate uniform light on all its surface would considerably improve the homogeneity of light delivery. The integration of plastic optical fibers into textile structures offers an interesting alternative. This article aims to describe briefly the technology used to develop light emitting fabrics (LEF) and their use in vitro (CELL‐LEF), in vivo (VIVO‐LEF) for experimental evaluation of PDT. Finally, the use of LEF for clinical applications is given by three examples. For in vitro applications, the CELL‐LEF device allows the illumination of several 96‐well cell culture plates. For the VIVO‐LEF, the system developed for PDT can treat three mice simultaneously with a homogeneous and high irradiance The medical LEF systems developed for PDT in dermatology for the treatment of actinic keratosis demonstrate their superiority thanks to a uniform light distribution due the flexibility of LEF. Interestingly, the technology used for manufacturing LEF is very well known by the textile industry, leading to very competitive production costs. The fact that optical fibers can transmit light from 400 to 1200 nm allows the connection of LEF to different laser sources covering the light spectrum of all photosensitizers used for medical applications. New developments should allow to use the LEF inside cavities such as the pleural or the peritoneal cavities.