Background: Different dementia syndromes display different patterns of everyday functioning. This article explored different patterns of functioning at baseline and trajectories of change in behavioral variant frontotemporal dementia (bvFTD) and Alzheimer disease (AD). Methods: Data from the Uniform Data Set of the National Alzheimer’s Coordinating Centre were employed. The Functional Assessment Questionnaire assessed functioning at up to 7 follow-up visits. Independent t tests assessed variations in functioning between syndromes at baseline. Linear mixed-effect modeling explored longitudinal functional trajectories between syndromes. Results: Data from 3351 patients (306 bvFTD and 3,045AD) were analyzed. At baseline, patients with bvFTD performed all daily activities poorer than AD dementia. Linear mixed models showed a significant effect of syndrome and time on functioning, and evidence of interaction between syndrome and time, with bvFTD showing a steeper decline for using the stove and travel. Conclusions: Findings can help in the effective care planning of everyday functioning for bvFTD and AD dementia.