Background   Exposure to a range of biological and psychosocial adversities in early childhood is of negative consequence through the lifecourse. This is particularly important for children in low- and middle-income countries where at least 250 million children are at high-risk of not meeting their developmental potential. Minimal evidence describes mothers' views of this. We therefore elicited an explanatory model exploring mothers' perceptions of infant stress and adversity in rural Haryana, India. Methods We did eight focus-group discussions to explore the perspectives of mothers in the general population of this rural area of India using a discussion guide based on Kleinman's explanatory model. Data were coded by two analysts and arranged in themes for presentation. Illustrative quotations were used for presentation of findings. Results All mothers identified several causes of adversity and stress for children, including poverty, neglect and violence. They described the consequences of this for emotions, behaviour and school readiness of children, and that some of the consequences were reversible with appropriate management. Mothers described younger children as being unable to be affected by adversity, because they were "too young to understand". Conclusions Mothers agreed with much of the current biomedical model for early childhood development, however the predominant view was that young infants were "too young to understand" is an important deviation. These findings are of importance in designing behaviour change strategies for this crucial period of early childhood which is rising up the global policy agenda with the aim of giving every child the opportunity to thrive.