Aim Most Japanese institutions screen for post‐partum depression (PPD) using the Edinburgh Postnatal Depression Scale (EPDS) at outpatient visits conducted at 2‐ and 4‐week post‐partum, but there are no published data on the usefulness of EPDS scores 2‐week post‐partum. In the present study, relationships between 2‐week post‐partum EPDS scores and 4‐week post‐partum EPDS scores were investigated to determine whether 2‐week scores may facilitate early intervention in high‐risk mothers. Methods A retrospective analysis of 451 deliveries from 2017 to 2019 was conducted at a single institution. EPDS scores were obtained using the Japanese EPDS 2‐ and 4‐week post‐partum, in conjunction with other perinatal data from medical records. Results In total, 334 of 451 mothers (74.1%) completed the EPDS at both 2‐ and 4‐week post‐partum and were included in the analysis. Of 48 who had higher scores 2‐week post‐partum, 21 (43.8%) continued to be at high risk of PPD. Of 284 who had lower scores 2‐week post‐partum, 9 (3.2%) transitioned to scores indicating high risk. Women considered high‐risk 4‐week post‐partum tended to have exhibited higher scores 2‐week post‐partum. Women who had experienced more deliveries tended to exhibit lower scores, and psychiatric illness was strongly associated with higher EPDS scores (odds ratio 11.2, 95% confidence interval 3.7–33.8, P < 0.01). Conclusion Two‐week EPDS scores closely reflected 4‐week scores, and may facilitate early intervention to prevent PPD. Primiparous mothers and those with a history of psychiatric illness should be followed‐up closely.