This study was done to identify sexual knowledge and perception and current status of sex education among parents of first and second grade elementary school age children. Methods: Participants in the study were recruited from parents with a child in the lower grades and who resided in Seoul. From January 1 to February 28, 2011, data were collected using a self-report questionnaire. Data were analyzed using McNemer test, paired t-test, ANONA, and Scheffé test. Results: Mean sexual knowledge scores for fathers and mothers were 27.74±4.94, and 28.62±4.70 respectively. Parent's sexual knowledge correlated with their occupation, education level, and family's monthly income. Conclusion: Study results showed that both parents are aware of the need for sex education. However, at home, mothers have a more active attitude towards sex education and conduct the education more often than fathers.