The process of dust release from aggregative cohesive powders under the action of mechanical vibration is studied. Beds of cohesive Potato Starch and Silica powders at fixed heights were vertically vibrated in a column in which vibration, frequency and acceleration levels can be independently set. Acceleration was changed with acceleration gravity ratio (a/g) values ranging between 5 and 9, while frequencies were set at 70 and 120 Hz. Vertical air flow rates through the bed were used to simulate air entrainment. Air in the head space above the bed was extracted and filtered in order to quantify the released dust rates. Results of these experiments are discussed and analyzed with reference to both the aggregative behavior of these powders and the inter-particle forces estimated from the bulk flow properties measured with conventional and standardized powder flow testers. A good relationship is found between the natural tendency of these powders to generate aggregates, the inter-particle forces and applied acceleration levels. Better insight of the physics is required to understand the effect of frequency on the dustiness of these powders.