Lack of insight is a core diagnostic criterion for behavioral variant frontotemporal dementia (bvFTD), and is believed to be intact in the early stages of primary progressive aphasia (PPA). In other neurological conditions, symptom-specific insight has been noted, with behavioral symptoms appearing especially vulnerable to reduced insight. Different components of insight, self-awareness and self-monitoring, are also often considered separate phenomena. The current study compared insight in patients with PPA, bvFTD, and probable Alzheimer's disease (PrAD) and a group of cognitively intact control subjects. Additionally, differences in insight for the domains primarily affected by the three types of dementia, namely, Behavior, Naming, and Memory, were assessed, and self-awareness and self-monitoring were compared. A total of 55 participants were enrolled. Participants were asked to complete self-estimate scales demonstrating their perceived ability immediately prior to, and immediately following a test in each domain of interest. Results indicated that PPA and normal control groups performed very similarly on control (Weight and Eyesight) and cognitive domains, whereas bvFTD and PrAD patients were unable to accurately assess Memory. All three diagnostic groups failed to accurately assess their behavioral symptoms, suggesting that this domain is vulnerable to loss of insight across diagnoses. Naming ability, in contrast, was either accurately assessed or underestimated in all groups. Finally, there were no notable differences between self-awareness and self-monitoring, potential explanations for this are examined.