The rotational molding characteristics of two ultra-low-density ethylene-alpha-olefin copolymers with elastomeric properties (polyolefin plastomers), made by metallocene catalysts, were investigated with the purpose of examining the effect of molecular structure on their processability. Particle coalescence and densification experiments revealed that higher comonomer content resulted in slower rates of coalescence and densification, thus affecting bubble content. Based on detailed material characterization, slower densification was attributed to the presence of broad melting endotherms, higher viscosity immediately after the melting transition, and higher melt elasticity. Investigation of the effect of particulate form revealed that use of powders instead of micropellets resulted in the formation of fewer bubbles on the outer surface, because of the broader particle size distribution, leading to improved appearance, better mechanical properties, and reduced overall processing time. Rotomolded parts displayed excellent impact properties and a high degree of flexibility.