Knowledge of detailed reproductive biology of cultivated species is important as requirements for fruit and seed production allow the development of effective management strategies and a sustainable use. Embryological processes of common buckwheat (Fagopyrum esculentum Moench) are difficult to interpret due to the influence of genetic determinants, i.e., dimorphic heterostyly resulting in the production of long- and short-styled flowers, and environmental predisposition, i.e., sensitivity of ovules to thermal stress. Furthermore, the situation is complicated by overproduction of flowers and depletion of resources as the plant ages. Herein we provide protocols that allow to visualize both basic and more specific embryological features and also disturbances in sexual reproduction of common buckwheat resulting from external and internal factors. All stages of plant material fixation, preparation, staining, and observation are described and explained in detail. Technical tips and pictures of properly prepared microscopic sections are also provided.