The determinants of the intention to stop childbearing tend to differ over time and contexts. This allows the issue of families' childbearing intentions to continually remain on the research agenda. As societal context and temporal variability will matter for second childbearing intentions, this study aimed at uncovering the reasons behind the intentions to stop childbearing from one-child mothers' perspective. A qualitative descriptive study in Isfahan City, Iran, was used to scrutinize reasons behind the unwillingness to have a second pregnancy. A purposeful sampling with maximum variation was used to select one-child mothers. Until reaching saturation, 48 semistructured interviews were conducted. A thematic analysis was used to analyse the qualitative data. Five themes and 19 subthemes emerged from the data analysis as structural attributes (economic, social and political conditions), parental attributes (parental (dis)agreements, childrearing troubles, having impatience and being at the inappropriate age for childbearing), husband attributes (having the intention to stop parenting, financially and emotionally nonsupportive and being busy by working), maternal attributes (health-related problems, adverse experience during former pregnancy, being employed, self-compassion, the fear of parity progression and being pessimistic) and child attributes (having a naughty child and having the physical or mental distress of the first child). Overall, findings highlight the multifaceted nature of factors influencing second childbearing intentions. Structural reasons at macro level, intrafamily relationship, mothers' self-related factors and challenges of raising the first child all play distinct roles in discouraging mothers from a second child intention. Understanding these key reasons can help policymakers, researchers and individuals alike to comprehend the complexities involved in family planning and fertility decisions.