Tempeh is an Indonesian traditional soyfood made by Rhizopus spp. fermentation. Tempeh has been well known as a vegetarian-friendly food and has been processed into various derived food products. This study aimed to develop an instant vegetarian cream soup from tempeh powder. The addition of tempeh powder was expected to increase the product’s antioxidant activity without compromising its physicochemical properties as an instant product. The five different formulations of cream soups containing 0–30% tempeh powder were analysed for their physicochemical properties (dissolving time, density, viscosity, colour, pH), antioxidant capacity (total phenolic content, total flavonoid content, DPPH radical scavenging activity, reducing power, and ferrous ion chelating ability), and hedonic test. Soup cream made with more tempeh power had a higher dissolving time, but
lower viscosity, lightness value, and pH value. However, their antioxidant activities also increased with the increase of tempeh powder added. From the hedonic analysis, the formulation with 15% tempeh powder showed the highest hedonic rate and therefore, was chosen as the best formulation. In conclusion, the addition of tempeh powder did not only give a better consumer acceptance but also higher antioxidant activities.