Aim: Postpartum depression is a highly prevalent disorder, and it has been recognized as a public health problem. In Chinese culture, after childbirth, women must stay at home for postpartum confinement. However, more than 50% of postpartum women tend to experience depression symptoms 3–4 days after delivery. Although the prevention and causes of postpartum depression have been extensively studied, the assessment tools used are usually based on Western cultures. A Chinese-version assessment scale was necessary. The objective of this study was to develop a culturally sensitive questionnaire for assessing the knowledge, attitude, and prevention behaviors toward postpartum depression of Taiwanese women, and examined the associations among postpartum depression knowledge, attitude, and prevention. Methods: Two-phase study was conducted. First, a postpartum depression scale was developed and its reliability and validity were tested in 50 people. Second, 639 postpartum women from seven hospitals were asked to complete the questionnaire. Results: The questionnaire, which contained four subscales and 16 questions (Cronbach's α = .82–.84), was administered in the postpartum room and required 5–10 min for completion. This questionnaire showed face validity and high acceptance, the factor analysis showed that the questionnaire has acceptable structural reliability. High scores on the postpartum depression knowledge and attitude subscales were associated with higher prevention behavior subscale scores. Conclusion: The finding of this questionnaire is an effective tool for determining postpartum women’s understanding of postpartum depression. Understanding postpartum depression knowledge, attitude and prevention are essential to assess and promote the postnatal care