Background: The use of humanoid-shaped robots may have a positive influence on older adults with dementia and their caregivers. However, there is a dearth of studies with a higher level of evidence. Thus, this quasi-experimental study serves as a preliminary investigation of using PALRO, a humanoid-shaped robot, in facilities' leisure programs for older adults with dementia. Objective: To elucidate the effects of a leisure program that uses the language-capable humanoid robot PALRO on older adults with dementia. Method: A one-group pretest-posttest design was done while employing Person-Centered Care principles and the associated outcome measure, Dementia Care Mapping (DCM). Older adults with dementia from long-term care facilities and group homes participated in a PALRO-facilitated leisure program. Data was collected using methodological observation to record the behaviors and well-being. Non-parametric inferential statistics were used to determine significant changes between pre-and post-intervention. Results: Among the 77 participants, 84.4% had a significant improvement in their well-being after the program. This improvement indicated a 'positive state' as defined in DCM. The participants elicited behaviors within the following categories during the program: interaction with an object, expressive activities, leisure activities, intellectual activities, articulation, and physical exercises. Conclusion: Significant percentage of older adults with dementia staying in long-term care facilities and group homes exhibited a 'positive state' towards a PALRO. The robot-mediated leisure program may be able to provide an opportunity to elicit positive reactions from older adults with dementia regardless of their level of cognitive functioning or independence.