Background: Over the past few years, various new types of technologies have been introduced, which have been tailored to meet the specific needs of older adults by incorporating gerontological design principles (i.e., "gerontechnologies"). However, it has been difficult to motivate older adults to adopt and use these new technologies. Therefore, it is crucial to better understand not only the role of personal drivers but also the family influences on older adults. Objective: This research goes beyond traditional technology acceptance theories by investigating the role of personal (e.g., inherent novelty seeking) and interpersonal drivers (e.g., influence of family) in stimulating older adults to use gerontechnologies. Nine hypotheses, building on traditional and new technology acceptance theories, were developed and tested. Methods: This research applies a cross-sectional study design. Therefore, a face-to-face survey instrument was developed building on a qualitative pilot study and validated scales. Three hundred and four older adults (minimum age = 70 years) were willing to participate as well as one of their family members. Structural equation modeling was applied to analyze the hypothesized conceptual model. Results: Our results extend the seminal technology acceptance theories by adding personal (i.e., inherent novelty seeking p = 0.017) and interpersonal drivers. More specifically, it was found that the attitude toward gerontechnologies was influenced by family tech savviness (i.e., people who often use technology), as this relationship is fully mediated through the social norms of older adults (p = 0.014). The same was found for older adults' trust in the family member's technology knowledge (p ≤ 0.001). Here, the relationship with older adults' attitude toward gerontechnologies was partially mediated by the older adults' trust in technology. Conclusion: This study identified important personal and interpersonal drivers that influence attitudes toward and intentions to use gerontechnologies. To foster technology acceptance among older adults, it was found that it is important to strengthen the trust in and the attitude toward gerontechnologies. Furthermore, family members' knowledge and beliefs in technology were the keys to promoting the actual use of gerontechnologies among older adults. Furthermore, the families' trust in gerontechnologies and the provision of access to technology can improve their attitudes toward technology and usage intentions for the older relative.