Urinary or double incontinence in frail elderly people is common and leads to a reduction in quality of life and an increased burden on the patients’ caregivers. Up to now, no special instrument has been available to assess the impact of incontinence on cognitively impaired patients and their professional caregivers. Thus, the outcomes of incontinence-specific medical and nursing interventions for cognitively impaired individuals are not measurable. Our aim was to investigate the impacts of urinary and double incontinence on both the affected patients and their caregivers using the newly developed “International Consultation on Incontinence Questionnaire Cognitively Impaired Elderly” (ICIQ-Cog) tool. The severity of incontinence was measured by incontinence episodes per night/per 24 h, the type of incontinence, the type of incontinence devices used, and the proportion of incontinence care out of total care; all these measures were correlated to the ICIQ-Cog. Incontinence episodes per night and the proportion of incontinence care out of total care showed significant correlations with the patient- and caregiver-related ICIQ-Cog scores. Both items have negative effects on patient quality of life and caregiver burden. Improving nocturnal incontinence and reducing the need for incontinence care overall can decrease the incontinence-specific bother of affected patients and their professional caregivers. The ICIQ-Cog can be used to verify the impacts of medical and nursing interventions.