Chronic insomnia and cognitive impairment are both common complaints among older adults. This study explores the association between chronic insomnia and changes in cognitive functioning among older adults. The study population comprised two groups: 64 older adults without insomnia and 35 older adult insomniacs. The cognitive capacity of each participant was tested at the participant's home using the computerized "MindFit" test (CogniFit, Inc.). In five categories of cognitive functioning, older adult insomniacs displayed impaired performance compared to older adult good sleepers. Specifically, significant differences were found between insomniacs and good sleepers on memory span, allocating attention to a target, time estimation, executive functioning, and integration of two dimensions (visual and semantic) tests. The findings imply that insomnia may have detrimental effects on some cognitive functions in healthy older adults.