Objective: In March 2021, modifications were made to the dietary guidelines for expectant and nursing mothers in Japan, resulting in an increased recommended gestational weight gain (GWG) based on the pre-pregnancy body mass index. However, the existing landscape of midwives’ health-guidance practices remains unexplored. This study aimed to elucidate the situation and perceptions of the revised GWG guidelines among midwives in Japan.Methods: This cross-sectional study, conducted between January and March 2023, targeted midwives employed across primary, secondary, and tertiary hospitals in Japan. The participants completed a web-based questionnaire via a QR code and provided responses. Descriptive analysis was employed to discern the midwives’ perceptions of the revised GWG guidelines.Results: A total of 160 midwives (24.2%) completed the web-based questionnaire and were included in the analysis. Of them, 117 (73.1%) knew the recommended GWG had been adjusted. A significant difference was observed in the self-evaluation of health guidance before and after the guideline change (p = .015). While 47.9% of the midwives viewed the guideline change positively, 50.4% considered it neither good nor detrimental. The reasons for this positive perspective included the perceived stringency of previous standards and concerns about the potential effects of strict weight guidance on the physical and mental health of both mothers and children. Those with a neutral stance gave the following reasons: 1) uncertainties about the post-change impact and 2) concerns regarding potential health implications for pregnant women gaining excessive weight.Conclusions: Because not all midwives were aware of the guideline adjustments, the new guidelines must be prioritized.