Abstract Objective The current study investigated relationships between neuropsychological test findings and instrumental activities of daily living (IADLs) in a mixed sample of Mild and Major Neurocognitive Disorder (NCD). Method Archival data from a memory disorder clinic were analyzed. Patients (n = 68, mean age = 72.3, mean education = 13.2 years, 26.5% Mild NCD, 73.5% Major NCD) minimally completed the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) and the Delis-Kaplan Executive Function System (D-KEFS). Information on IADLs was obtained from family members via the Functional Activities Questionnaire (FAQ). Spearman correlations were calculated between individual IADLs from the FAQ, total FAQ ratings, RBANS index scores, and a composite executive functioning score (average scaled score on DKEFS Trail Making, Verbal Fluency, and Tower). Results Executive functioning was the only cognitive domain that significantly correlated (p < .05) with total FAQ ratings. However, all cognitive domains except language significantly correlated with individual IADLs. Tracking current events correlated with immediate memory, while financial management correlated with delayed memory. Attending to, understanding, and discussing TV, books, and magazines correlated with executive functioning and immediate and delayed memory. Remembering events correlated with attention and executive functioning. Shopping alone correlated with immediate memory, attention, and executive functioning, while operating basic kitchen appliances correlated with visuospatial skills, attention, and executive functioning. Traveling also correlated with visuospatial skills and executive functioning. Conclusions Executive functioning was the only domain associated with overall daily functioning; however, all domains except language corresponded with individual IADLs. Current findings highlight the utility of neuropsychological test findings in understanding the nuances of deficits in daily functioning.