Measurements of lysozyme diffusion within the "depletion zone" of the (1 1 0) face of lysozyme crystals are reported. The measurements were performed using the technique of microscope light scattering, capable of measuring small sampling areas (similar to 2 mum(2)). Measurements within such small areas allowed for the determination of intensity correlation functions at precise locations (at similar to 10 mum intervals) adjacent to the (1 1 0) crystal face. From the intensity correlation functions, diffusion coefficients of lysozyme molecules adjacent to the (1 1 0) crystal face and in solution were determined. The diffusion coefficients were observed to decrease as the surface of the crystal was approached, Published by Elsevier Science B.V.