The "familiarity effect" (Shen and Reingold, "Perception & Psychophysics" 63(3):464-475, 2001) is a phenomenon in which unfamiliar symbols perceptually "pop-out" when placed among familiar symbols (e.g., letters). In contrast, searching for familiar symbols among unfamiliar symbols is more challenging. Failure to account for effects such as these when predicting search performance could lead to overconfidence and error. This study investigated metacognitive awareness of the familiarity effect by asking participants to rate the speed and accuracy of search before they searched for either letter or symbol targets among letter or symbol distractors. Feature overlap between target and distractor and target presence or absence were also manipulated to provide concurrent cues to task difficulty. This study examined metacognitive awareness of the "familiarity effect," and extended the findings from an earlier metasearch study (Redford et al., "Memory and Cognition" 39:1534-1545, 2011). Metacognition was accurate with respect to the familiarity effect. However, participants incorrectly predicted that they would detect a target's absence faster than its presence. These findings suggest that people have metacognitive awareness for some aspects of visual search, even when patterns of search performance are complex and potentially counterintuitive. However, limitations exist in our metacognitive awareness of visual search. The results are discussed in relation to Koriat's cue utilization framework and heuristic-based metacognition.