Children's diets are important determinants of their health, but typically do not meet recommendations. Parents' feeding practices, such as pressure or restriction, are important influences on child diets, but reasons why parents use particular feeding practices, and malleability of such practices, are not well understood. This qualitative study aimed to explore mothers' perceptions of influences on their feeding practices, and assess whether an intervention promoting recommended feeding practices was perceived as influential. The Melbourne Infant Feeding, Activity and Nutrition Trial (InFANT) Program was a cluster-randomised controlled trial involving 542 families aiming to improve child diets. Following the trial, when children were two years old, 81 intervention arm mothers were invited to participate in qualitative interviews, and 26 accepted (32%). Thematic analysis of interview transcripts used a tabular thematic framework. Eight major themes were identified regarding perceived influences on child feeding practices. Broadly these encompassed: practical considerations, family setting, formal information sources, parents' own upbringing, learning from friends and family, learning from child and experiences, and parents' beliefs about food and feeding. Additionally, the Melbourne InFANT Program was perceived by most respondents as influential. In particular, many mothers reported being previously unaware of some recommended feeding practices, and that learning and adopting those practices made child feeding easier. These findings suggest that a variety of influences impact mothers' child feeding practices. Health practitioners should consider these factors in providing feeding advice to parents, and researchers should consider these factors in planning interventions.