Companies start their lives as startups, privately funded, small, focused, and not profitable. As they mature, they often become publicly traded, profitable, much bigger, and involved in multiple projects. Christensen (1997) found that startup companies are more innovative than mature companies. Amabile (1988), Ekvall (1996), and others developed a list of organizational factors affecting the creativity of individuals in organizations. The purpose of this study is to explore the differences in the organizational climate and personal context for creativity between mature companies and startup companies, and the resulting differences in the level of experienced individual creativity between those companies. This exploratory, interview based case study used a sample of 20 participants who worked for both startup and mature companies, and explored the differences in the participants' experiences of creativity and the factors contributing to, or inhibiting creativity. This study found that individuals experienced higher degree of creativity in startup companies than in mature ones, that the organizational factors conducive to creativity were perceived as higher in the startup companies, while the organizational factors inhibiting creativity were perceived as higher in the mature companies, explaining the experienced higher degree of individual creativity in startup companies, and potentially explaining why startup companies are more innovative than mature ones. The study did not find significant differences in personal context factors between the two types of companies.