In Québec, 83 first-generation seed orchards destined to produce seeds from genetically improved trees have been established since 1973. Consequently, the Tree Genetic Improvement Program uses a very large quantity of pollen in order to carry out the controlled pollination projects in those seed orchards. Moreover, controlled pollination is carried out within a very short time-frame and very often the receptivity period occurs before the time of pollen dispersion. It is for these reasons that the pollen bank was created in Québec. This manuscript summarize the process of long term preservation of a large quantity of tree pollen. It is possible to preserve the pollen of coniferous trees on a large scale for up to five years. It is more difficult to manipulate the pollen of deciduous trees.