Dust samples from blast furnace dust catchers and cast house dedusting system ere investigated with respect to flowability-relevant parameters. The mass median diameter of the dusts was in the range of 140 to 210 mu m for the dust catcher dusts and approximately 6 mu m for the cast house dusts. Generally, the flowability of the dust catcher dusts was better compared to the flowability of the cast house dusts. The flowability', categories suggested by, the three flowability indicators the angle of repose, Hausner ratio, and Carr's compressibility-were good for the coarser dusts, while for the finer dusts the flowability was overestimated. For the blast furnace dusts, from the dust catcher a considerable variation in the bulk density was found, which can presumably be attributed to the remarkable difference in the carbon content of the dusts investigated.