The use of thiol-ene click chemistry is demonstrated for the first time as a suitable method for cross-linking thin films of 4-phenylethenyl end-capped poly(fluorene). Cross-linking was accomplished by a simple, brief UV curing step at modest temperatures. This chemistry provides an advantage over similar schemes employed for cross-linking conjugated polymers since it does not require elevated temperature or produce potentially detrimental side products. Thiol-ene cross-linking was found to preserve the emissive color integrity of the poly(fluorene) films and allowed for facile photopatteming of the active polymer layer. Furthermore, the investigated cross-linking chemistry was shown to be fully compatible with fabrication of polymer light-emitting diodes (PLEDs) whose performance was comparable to noncross-linked devices. Multicolor PLEDs were also demonstrated by taking advantage of the photopatternability of the thiol-ene based system.