AbstractObjective:Chronic aflatoxin exposure has been associated with childhood stunting (length-for-age/height-for-age < –2 sd), while data lacks for Bangladesh, a country with substantial burden of childhood stunting. This paper examined the association between aflatoxin exposure and childhood stunting in a slum setting of Dhaka city.Design:In this MAL-ED aflatoxin birth cohort study, plasma samples were assayed for aflatoxin B1-lysine adduct (AFB1-lys) by MS at 7, 15, 24 and 36 months of age for 208, 196, 173 and 167 children to assess chronic aflatoxin exposure. Relationship between aflatoxin exposure and anthropometric measures was examined by mixed-effects logistic regression models.Setting and participants:The study was conducted in Mirpur, Dhaka, where children were followed from birth to 36 months.Results:Prevalence of stunting increased from 21 % at 7 months to 49 % at 36 months of age. Mean AFB1-lys concentrations at 7, 15, 24 and 36 months were 1·30 (range 0·09–5·79), 1·52 (range 0·06–6·35), 3·43 (range 0·15–65·60) and 3·70 (range 0·09–126·54) pg/mg albumin, respectively, and the percentage of children with detectable AFB1-lys was 10, 21, 18 and 62 %, respectively. No association was observed between aflatoxin exposure and stunting in multivariable analyses. Factors associated with childhood stunting were age, low birth weight, maternal height, stool myeloperoxidase and number of people sleeping in one room.Conclusions:A relatively lower exposure to aflatoxin may not influence the linear growth of children. This finding indicates a threshold level of exposure for linear growth deficit and further investigation in other areas where higher concentrations of aflatoxin exposure exist.