The present study examined the role of target and judge interaction demands on first impression accuracy (n = 195). Specifically, the role of targets' self-presentation concerns and judges' information processing demands on accuracy for interpersonal traits (i.e., traits likely to be accentuated within an interpersonal context) and less interpersonal traits (i.e., traits less likely to be accentuated within an interpersonal context) was examined. Pairs of unacquainted participants (n = 88; females = 52, males = 36) interacted for ten-minutes in one of three interaction conditions that sought to vary interaction demands by manipulating the degree to which participants were aware of judging and/or being judged. Accuracy was assessed by correlating judgements formed with a measure of target's personality that comprised an average of self-ratings and informant-ratings (n = 107). Findings revealed that in interaction conditions where there was a mismatch in evaluation expectations – when a participant knows he or she will judge but not that he or she will be judged – accuracy for “less interpersonal” traits is diminished. Findings are discussed in relation to Patterson's (1995) parallel process model of interpersonal communication and Funder's realistic accuracy model (1995). Limitations in terms of the generalisability of the findings are discussed.