Microscopy techniques for direct visualization of phases in polymer blends are reviewed. Light microscopy is suitable for immiscible blends and contrast techniques include polarized light, phase contrast, differential interference contrast, and fluorescence. Each technique has an application for a particular polymer system. Scanning electron microscopy is used for study of surface morphology and contrast can be enhanced by electron beam damage or by chemical etching. Cutting often provides sufficient contrast, but surface preparation by fracture or by solvent extraction must be used with caution. Surface carbon replica is a good alternative that provides better resolution and contrast. A new technique of selective swelling will be discussed. Transmission electron microscopy has very good resolution and can thus be used for the study of very fine dispersion in miscible blends. Contrast can be enhanced electronically or by staining of pre-irradiated samples. It will be shown that the latter, together with mass loss measurements, can provide some new and unique information on the polymer blend system. Crystallographic studies are limited by the beam damage. It is nevertheless possible with some specialized techniques (STEM and microdiffraction) to obtain several dark field images and diffraction patterns from one area of highly beam sensitive polymers.