Résumé : This cross-sectional study was conducted to determine the association between selected characteristics and body composition of mothers and children in early life. This study included 213 mother–child pairs 6 to 8 months involving in the cohort study of the Research and Development Project conducted in Kaffrine district. The main outcomes were fat-free mass (FFM) and body fat (BF), measured using deuterium dilution method and anthropometry. Independent variables were sociodemographic, dietary diversity and health characteristics. Descriptive, correlation, bivariate and multiple regression analyses were conducted. According to body mass index (BMI), 23% of mothers were underweight, 12% were overweight/obese and 11% had excess BF. Four per cent of children were below −2 weight-for-length z-score (WLZ), 10% were below −2 length-for-age z-score (LAZ) and 40% had excess BF. Maternal FFM was positively correlated with child FFM (r = 0.25, P = 0.002). Similarly, mothers' BMI, FFM and BF were significantly and positively correlated with children's LAZ. Stepwise regression showed an increased association between minimum dietary diversity (MDD) and WLZ score, FFM and BF of children. Among mothers, being employee and doing reproductive health care were determinants of higher BMI, FFM and BF. This study found a strong association between maternal and child body composition in early life. Adequate diet is the main determinant of children nutritional status. Among the mothers, having a job and doing primary health care seem to be beneficial for the nutritional status. Improvement of women's empowerment, quality of health care and dietary diversity could have a positive impact on maternal and child nutrition.