Sunflower- and rape-seed samples were collected in French grain silos (34 in 2002 and 121 in 2003), at the surface of bulked grain with the method of surface non-random sampling during the spring season. Insects were counted after sample sieving and species identified and sorted in different groups of nuisibility. In rapeseeds, very few pests were found, except mites. On the other hand, sunflower-seed samples were regularly infested, mainly by secondary and mycophagous insects, which do not damage seeds. A parallel survey carried out among 85 grain store managers was processed to set up the relationships between the storage structures characteristics, the storage management practices and the pest infestation risks. It showed that good storage practices are limiting storage insects’ occurrence.