Adipose-derived stem cells (AdSCs), a type of mesenchymal stem cell, are expected to be applicable to regenerative medicine and cellular delivery systems. The maintenance of cell multipotency and control of the differentiation direction are important for these applications. However, the differentiation direction of these cells is widely believed to depend on the physical properties of their scaffold. In this study, we explored whether the multipotency of AdSCs, that is, their ability to differentiate into multiple cells, is maintained when they are removed from injectable polymer (IP) hydrogels with various degrees of cross-linking and induced to differentiate into osteoblasts and adipocytes. We confirmed that AdSCs cultured in IP hydrogels maintained an undifferentiated state. However, their differentiation into osteoblasts and adipocytes cannot be ensured; specifically, the multipotency of AdSCs may decrease when they are cultured in IP hydrogels. When cultured in an IP hydrogel with extreme softness and poor cell adhesion properties, the AdSCs remained in an undifferentiated state, but their multipotency was reduced. These results provide important insights into stem cell delivery systems using IP hydrogels.