The effects of rheological properties of the wall materials on the morphology and particle size distribution of microcapsules prepared by spray-drying were evaluated. Gelatin-sucrose (Gel-Suc), gelatin-peach-gum-sucrose (Gel-PG-Suc), and HI-CAP 100 were used as wall materials with vitamin A as a model core material. Scanning electron microscopy (SEM) showed that microcapsules produced with Gel-Suc exhibited cracks while Gel-PG-Suc produced a smooth surface with few pores, and HI-CAP100 a rounded surface containing characteristic concavities. The volume average diameter (D<sub>4,3</sub>) showed significant variations from 73.9 &plusmn; 1.02 &micro;m and 68.7 &plusmn; 0.85 &micro;m to 29.9 &plusmn; 0.94 &micro;m (P &lt; 0.05). Rheometry indicated that the wall paste viscosity was inversely proportional to the shear rate. Viscosity ranking was Gel-Suc &gt; Gel-PG-Suc &gt; HI-CAP 100. Gel-Suc showed the highest elastic modulus (G') and viscous modulus (G'' values), followed by Gel-PG-Suc and HI-CAP 100. Gel-Suc was associated with moderate quantities of broken microcapsules while HI-CAP 100 generated numerous microcapsules with characteristic dents generated during spray-drying.