The growth of the older population worldwide has been followed by an increase of mental illness, an important cause of morbidity. In the elderly, the coexistence of disability, physical and mental illness and social problems means that older people often have complex needs, which require comprehensive and systematic assessment.

To identify met and unmet needs and their relationship with cognition and functionality.

Elderly patients (≥ 65 years old), with mental disorders (ICD-9), were recruited consecutively from ULSAM, in Portugal.

All patients were assessed with the Camberwell Assessment of Need for the Elderly/CANE, Mini Mental State Examination/MMSE, Clock Draw Test/CDT, Geriatric Depression Scale/GDS, Zung Anxiety Scale/ZAS, Barthel Index/BI and Lawton & Brody Index/LI.

In this sample (n=306), the most frequent unmet needs were daytime activities (46.7%), psychological distress (25.8%), memory (13.4%), social benefits (11.4%) and company (8.2%).

A significant relation between global needs - CANE (met and unmet) and psychiatric diagnoses (F=12,888, p=.000) was found. Patients with dementia had a higher number of global needs and lower functionality.

The global needs correlated negatively with MMSE (r=−.666, p=.000), CDT (r=−.512, p=.000), BI (r =−.541, p=.000) and LI (r =−.854, p=.000), and positively with GDS (r =.385, p=.000).

Cognitive deficits, higher depression and lower functionality were associated with a greater number of needs. These results also suggest that dementia is an important determinant of the functional status and needs.