Aerosols of biological origin (bioaerosols) are an important fraction of the complex of particles suspended in the air. Propagules such as: pollen grains, fungal spores, algae or dinoflagellates cysts, also with bacteria and viruses, can be transported long distances, causing diseases in plants, animals, and humans with consequences for agriculture and health. Moreover, in their atmospheric transit, they often act as condensation or ice nuclei, affecting the hydrological cycle or the climate. Despite the numerous works related to these issues, the processes by which they are emitted, interact or are removed from the atmosphere, are poorly understood. This paper presents a comprehensive review about the study techniques, the knowledge of processes and interactions among bioaerosols, atmosphere, and surfaces from which they are emitted or deposited, as well as the effects on agriculture, health and the role of bioaerosols in the climate system.