A simple fluorescence technique Is proposed for the measurement of the diffusion. coefficient of oxygen into latex films. These latex films were prepared by annealing pyrene (P) labeled polymethyl methacrylate (PMMA) particles above the glass transition temperature, Transparency of these films were measured by monitoring the transmitted photon intensity, I-tr, which increased as the annealing temperature war increased. Steady state fluorescence was used to monitor oxygen diffusion into latex films. Diffusion coefficients, D, of oxygen were determined using fluorescence quenching method and are found to be around 5.6 x 10(-11) cm(2)s(-1).