▪ Abstract  Recent progress on the use of near-field scanning optical microscopy (NSOM) to characterize organic thin film materials is extensively reviewed. NSOM is leading to important new information on the morphology and spatially resolved optical properties of a variety of materials, complementing more widely available methods for thin film analysis. Materials described in this review include polymer thin films, molecular aggregates, molecular crystals, molecular semiconductor heterojunctions, biological materials, and molecular mono-, bi-, and multi-layer films.