Objective To gain an in-depth understanding of infant and young child feeding practices, accompanying beliefs and their sociocultural context in the Karen and Lua ethnic communities of northern Thailand.Design A two-day workshop and thirty in-depth interviews were undertaken in June 2014. Dialogue occurred with the assistance of translators and was recorded, transcribed and translated. A detailed thematic analysis was undertaken.Setting Northern Thai indigenous communities in which one-third of the children under 5 years of age are stunted.Subjects People with various roles in the local health system and twenty-six villagers who cared for infants and young children.Results Predominant breast-feeding was said to occur for 1 to 3 months but was not exclusive due to early introduction of water and/or rice. Exclusive breast-feeding for 6 months was impeded by the need for mothers to return to farming work, with the early introduction of solids enabling infants to be cared for by other family members. Low variety in complementary foods was typical during infancy, with few local foods having appropriate texture and special preparation of foods rarely described. A pervasive underlying issue is women's responsibility to labour and lack of time to care for their young children. Poverty and food insecurity also featured in participants' accounts.Conclusions In combination, women's limited time to care, poverty and food insecurity are perpetuating poor nutrition of children in early life. Agricultural solutions that are being explored should also attend to the burden of work for women.