The orientation of individual urediniospores and spore clusters of Uromyces viciae-fabae, during fall and after landing in still air, was recorded using high-speed video microscopy. Individual spores and aggregates fell in a variety of orientations. On landing spore clusters attached to the substratum without rebounding or fragmenting and typically retained their orientation during fall. Some aggregates landed and attached in orientations in which their mass was asymmetrical with respect to their point of contact. Attachment also occurred when spores fell onto spore aggregates which had previously landed on the substratum. Rate of fall was influenced by the orientation and size of cluster. When dispersed and collected on substrata under simulated field conditions, the orientation and attachment of urediniospore clusters were similar to those of aggregates deposited in still air.