The objective of this pilot study was to explore the effects of occupational therapy on the performance of daily activities by older individuals with cognitive impairments and on the sense of competence of their primary caregivers. The design was a single group design. Older individuals with cognitive impairments and their primary caregivers were assessed prior to the first occupational therapy visit in hospital and after 5 weeks of occupational therapy at home. Participants were older individuals with mild to moderate cognitive impairments living at home (n = 12) and their primary caregivers (n = 12). These older clients with cognitive impairments and their primary caregivers received an occupational therapy intervention in hospital and at home after discharge in accordance with an occupational therapy guideline. This guideline is client-centered and makes use of collaborative, psychosocial, and environmental approaches. The main outcome measures were older clients' motor and process skills, initiative, need for assistance, self-perception in occupational performance, and satisfaction with this performance in daily activities and primary caregivers' sense of competence. The results of this study indicated that older clients' motor and process skills and self-perception in occupational performance improved and that they needed less help. The sense of competence of their primary caregivers also improved. This study provides preliminary evidence for the effectiveness of occupational therapy in older individuals with cognitive impairments and their primary caregivers, which should be tested in a randomized, controlled trial.