Delayed onset of lactogenesis is a significant barrier to achieving the WHO-recommended 50% exclusive breastfeeding rate in the first six months. This study maps the main factors influencing this condition, addressing gaps in the current research landscape. Following Arksey and O'Malley's scoping review framework, databases such as PubMed, Web of Science (WOS), Embase, Cochrane Library, CINAHL plus with full text, China National Knowledge Infrastructure (CNIK), Weipu Chinese Journal Service Platform (VIP), Wanfang Data Knowledge Service Platform, and China Biomedical Literature Database (CBM) were searched on February 1, 2023. Studies in Chinese and English involving pregnant and postpartum women, focusing on delayed onset of lactogenesis, were included without restrictions on publication date or geography. Forty-six studies published between 2002 and 2022 met the inclusion criteria, revealing variable incidences of delayed lactogenesis among different groups. Thirty-four influencing factors were identified and organized into five themes: maternal-infant characteristics, perinatal mental state, physical activity participation during pregnancy, breastfeeding behaviors, and medical staff interventions. Within eighteen major factors highlighted, factors such as age, pre-pregnancy BMI, gestational weight gain, average LATCH score within 24 hours postpartum, labor analgesia, sleep, frequency of postpartum breastfeeding, and timing of initial breast suckling/pumping showed inconsistent or conflicting conclusions. High and variable incidences of delayed lactogenesis underline its multifactorial nature. Effective interventions require strong advocacy from healthcare professionals and adherence by pregnant women. Further research using standardized methods is essential to clarify inconsistent or conflicting findings on the influencing factors.