Prior research has found that perceiving positive responses from others following self-disclosures enhances social bonds and plays a role in the maintenance of romantic relationships. We sought to extend this effect by exploring perceived responsiveness to good news in the context of initial social interactions with a stranger. In this study, unacquainted college students (n = 106) participated in a 45-minute semi-structured social interaction, and information on their emotions and behaviours was collected immediately after and one week later. We found that the receipt of supportive reactions to self-disclosure attempts during the social interaction was associated with immediate positivity and a more positive memory of the event (remembered enjoyment and positive emotions) one week later. This effect could not be attributed to how positively the event was experienced immediately afterwards, suggesting that perceived responsiveness during an initial social interaction facilitates a positive memory bias. These results offer new insights into how friendships might develop and be maintained.