Gauging one's impression on a potential mate is challenging. There is a need to make reasonably accurate inferences from subtle, dynamic facial expressions and to maintain motivation to connect despite the risk of rejection. The interpersonal optimism of people low in rejection sensitivity (RS), people who confidently expect acceptance rather than anxiously expect rejection, as do their high RS counterparts, suggests that they may strategically underestimate social threat cues when inferring the impression they have made on others. To test this hypothesis, participants viewed the videotaped reactions of individuals said to have read the participant's own or someone else's biographical sketch in an online dating context, and then estimated the emotions of the targets. Estimates of negativity were unrelated to RS when participants believed the videos captured the reactions to someone else's biographical sketch. However, to the extent that participants were low in RS, they made lower estimates of negativity when they believed the videos showed reactions to their biographical sketch compared to when they believed the videos captured the reactions to someone else's biographical sketch. The tracking accuracy of participants estimating negativity was unrelated to RS under either condition, but increased with trait empathy. RS was unrelated to estimates of positivity. Supporting functional perspectives on interpersonal perception, results show that interpersonal optimism shapes impressions of others' reactions to the self in ways that can foster relationship initiation.