Research has extensively studied adult attachment theory, a fundamental psychological framework, particularly regarding its implications for adult attachment and sexual dynamics. The previous literature has established relationships between adult attachment and various sexual behaviours as well as communication patterns. Specifically, individuals with secure attachment styles typically engage in open communication and cautious sexual behaviours, whereas individuals with anxious or avoidant attachment styles exhibit less sexual communication and engage in riskier sexual activities. That said, limited research has explored the relationship between adult attachment style and perceived knowledge regarding partner sex history. This study aimed to fill this gap by investigating how adult attachment style relates to perceived knowledge about partner sexual experiences. A sample of 237 undergraduate students completed surveys assessing attachment style and their perceived awareness of their partner’s sexual past. Attachment style was evaluated using the Revised Adult Attachment Scale (RAAS) and perceived knowledge was measured using the Partner Sexual History Scale (PSHS). The results indicated a significant correlation between adult attachment style and perceived knowledge of a partner’s sexual history. Specifically, individuals with secure and avoidant attachment styles demonstrated greater perceived awareness of their partner’s sexual experiences compared to those with an anxious attachment style. This research contributes to our comprehension of the complex interplay among adult attachment, sexual knowledge, sexual communication, and relationship dynamics in young adult populations.