The present work reports a simple approach to manufacture electrocatalytically active gas diffusion electrodes (GDEs) in two steps: (i) inkjet printing and (ii) flash light irradiation from a xenon flash lamp, a process called Print-light-synthesis (PLS). Pt/C PLS GDEs were manufactured from a Pt precursor ink printed directly over a carbon paper gas diffusion layer (GDL) with a microporous layer (MPL) of carbon with a metal precursor loading of 0.5 mgPt−1 cm−2, the precursor film was then exposed to flash light irradiation at 450 V-pulse for 100 ms. SEM images showed a uniform and thin Pt catalyst layer deposited on top of the GDL. XRD and XPS spectra evidenced metallic Pt with face-centered cubic crystalline structures. TEM analysis provided an average particle size of 5.0 ± 0.3 nm with uniform particle distribution over the MPL. Electrochemical characterization was performed on half-cell and fuel cell setups showing electrocatalytic performances comparable to that of a reference GDE Pt/C. Pt/C PLS shows even better fuel cell performance per gram of Pt catalyst compared to the reference Pt/C. This work shows that PLS is a very simple approach, e.g. to manufacture GDEs on a roll-to-roll basis for applications in energy conversion devices such as fuel cells, batteries, electrolyzers, etc.