Background: Childhood overweight poses health risks and often persists into adulthood, making early intervention essential. Swedish Child Health Service (CHS) nurses are responsible for addressing this issue, a task perceived as important yet challenging. When giving support to these families a caring and person-centered approach is crucial for their well-being and adherence. Childhood overweight is often associated with parental overweight. Due to the sensitivity and stigma surrounding adult overweight, healthcare professionals may experience discomfort, potentially leading to negatively perceived interactions with patients. Despite these challenges, little is known about how parental overweight influences CHS nurses’ approach in encounters regarding children´s overweight. Therefore, this study aimed to explore how CHS nurses support parents with overweight in clinical encounters where children have overweight. Methods: A qualitative design was applied. Semi-structured video interviews were conducted with 14 CHS nurses, and transcripts were analysed using latent, inductive content analysis. Results: Four categories were identified: Feeling insecurity regarding professional role, Focusing on concrete aspects of health, Questioning the parents, and Trying to influence the parent. CHS nurses perceived addressing the child’s overweight as their primary duty. They focused on weight-related aspects of the child’s health, often emphasising lifestyle advice, while parents’ emotions or socioeconomic challenges risked being overlooked. Parental overweight could trigger negative assumptions, including doubts about parents’ ability to support their child. When children’s weight curves remained unchanged, frustration sometimes led nurses to emphasise parental responsibility or use threats, such as involving child welfare services. Conclusion: This study highlights how CHS nurses perceive both challenges and responsibility in addressing childhood overweight, difficulties that intensify when parents themselves have overweight. The findings indicate that while striving to fulfil their role, CHS nurses’ approaches are shaped by weight stigma and by the struggle to balance professional responsibility with maintaining a supportive and respectful, person-centered approach.