Introduction <p>The topic of sex education is frequently discussed in academic and public discourse. While it is often considered and evaluated through the lens of values, its importance for psychosexual development is indisputable. The present study investigated the hypotheses that sex education was positively related to sexual satisfaction and that sexual self-awareness positively mediated between the level of sex education and sexual satisfaction. </p> Methods <p>The sample comprised 1,168 individuals drawn from the general Polish population, with data collected in 2022 and 2023. The study comprised a total of 786 female participants and 297 male participants. The average age of the participants was 21.70 (<i>SD</i> = 4.49). Three measures were designed and validated; the first one was used to assess the level of knowledge about sexual education, the second one to evaluate the level of knowledge about self-sexuality, and the third one to examine satisfaction with one’s sexual life.</p> Results <p>The measures showed good psychometric properties. The hypotheses were tested using mediation analysis. The level of sex education was positively related to sexual satisfaction (β = 0.21), and the indirect effect attributed to sexual self-awareness was positive (β = 0.10) and statistically significant. As robustness analyses indicated, the hypothesized model appeared to be the most plausible structure of the tested relationships.</p> Conclusions <p>Sexual self-awareness, next to sex education, is an essential factor related to sexual satisfaction. All these factors can contribute to a higher quality of sexual life. Policy Implications: Comprehensive sex education interventions targeting sexual self-awareness can significantly improve the sexual satisfaction and overall well-being of adult individuals.</p>