The role of information context, judgment perspective and cue type on the “accuracy” of first impressions of another’s Big5 personality was studied in three phases of data collection (n = 173). Accurate judgments were defined as the level of agreement between a target person’s aggregated personality score (i.e., average of self and informant ratings of personality) and a personality judgement about the target, indexed using item correlations. Results for Phase 1 found that completing a different task with the same partner improved accuracy for conscientiousness. Phase 2 investigated the relationship between a person’s role (judgment perspective) within an interaction (interactants, observers) and showed that Observers were better at judging the less interpersonal traits of conscientiousness and openness relative to Interactants. Finally, Phase 3 examined the types of cues that people used when rating another’s personality. Although Observers and Interactants had access to the same interaction, analyses revealed that they employed different types of cues when judging others. Findings are discussed in terms of Funder’s Realistic Accuracy Model (1995, 1999) along with practical implications, limitations and suggestions for future research.