ObjectiveTo survey knowledge about the factors that influence fertility in a reproductive-age population living in an urban area.MethodsA cross-sectional study was conducted using a questionnaire-based survey among both males and females aged 18–45 years living in the Bangkok metropolitan area.ResultsThe mean age of the participants was 26.8±7.2 years (male, 41.9%; female, 58.1%). Of the participants, 53.1% had an undergraduate degree and 57.1% were single. Only one-fifth of the participants correctly identified the age when fecundity declines in male and female, the definition of infertility, and the period during the menstrual cycle with the highest chance of pregnancy. Approximately three-fourths of the participants correctly identified that cigarette smoking, alcohol consumption, and sexually transmitted infections affect fertility.ConclusionA considerable knowledge gap about the factors that influence fertility was identified in reproductive-age individuals in an urban area of Thailand. This issue should be urgently addressed by promoting fertility awareness through education, discussions about social perceptions regarding fertility, and reliable sources of knowledge.