Background: Clinical evaluation of novel assistive technologies is of utmost importance, as this would help in making such technologies practical and ensuring that they suit the user's requirements. Objective: The purpose of this study is to develop a new methodology for the addition of user and user's life centered clinical evaluation of assistive technologies (ULCEAT) to conventional evaluation methods. The proposed ULCEAT methodology consists of two steps: evaluation by rehabilitation professionals and evaluation by potential users. These evaluations were performed to identify target users and to ensure the effective use of new assistive technologies (ATs); the evaluations were based primarily on qualitative research involving the rehabilitation professionals and the potential users. Methods: The methodology was demonstrated by using it for the clinical evaluation of Roboticbed®, which was developed by the Panasonic Corporation. Results: The effective use of Roboticbed® was confirmed on the basis of the results, and three target user types were identified. The validity of this methodology was further confirmed by a user evaluation of Roboticbed® in an experimental environment. Conclusions: The findings of this study will be used to help conduct conventional clinical evaluations for novel and prototype ATs.