This paper presents the experimental results of a study on the porosity of powder coatings in a laboratory fluidized bed. A commercial paint powder, Levasint(R) S31, was used to coat copper cylinders of different diameters. The effects of process variables such as coating temperature, air velocity and dipping time on the porosity of the coating were studied. The porosity and thickness were measured by image analysis. It is found that coating temperature plays an important role in determining the quality of the coating. The minimum temperature required for Levasint S31 to achievE 5% or less porosity is about 200 degrees-C. The air velocity and dipping time are also found to have significant effects on the porosity.