Recent trends of new venture startups have paved the way for the expansion of the design industry and opened new windows of opportunity for the traditionally small and non-specialized design business. In this environment, design startups are rapidly growing in modern society, and thus meeting the needs of consumers through the development of innovative products, processes, and services. This study aims to determine the critical success factors affecting design startups. To this end, the concept and success variables of startup businesses were studied based on previous research, and then key success factors of design startups were identified. A total of 24 experts, from 12 design-based small venture startups and 12 technology-based small and medium startups, were surveyed regarding their priorities related to these factors, using the analytic hierarchy process (AHP). The results suggest that idea commercialization is the most important success factor as an innovation criterion among the four success criteria of design startups. Hence, entrepreneurial conditions, such as goal-orientation and entrepreneurs' competence, are important success factors for design startups.