Pre-pregnancy overweight and obesity is associated with shorter breastfeeding (BF) duration. Whether pre-pregnancy overweight and obesity is associated with other aspects of infant and young child feeding (IYCF) has not been investigated. We used data from 370 children born January 1999–September 2001 in a semi-urban community in Morelos, Mexico, where information on how they were fed was available at 1, 3, 6, 9, 12, 18 and 24 months of age. We modified the World Health Organization's dietary diversity indicator to assess the quality of the complementary foods. An index that included BF, quality of complementary foods and other behaviours was constructed to measure IYCF. We used survival analysis to examine the association of pre-pregnancy body mass index (pBMI) category and BF duration and mixed models for quality of complementary food and IYCF index. Mean maternal pBMI was 24.4 ± 4.1; 31% were overweight, and 9% were obese. pBMI was not associated with BF duration. Quality of complementary food improved over time (6 months, 1.3 ± 1.3; 24 months, 3.8 ± 1.04). Compared with normal-weight women, overweight and obese women were more likely to feed from more food groups (0.24 ± 0.11 point, P = 0.03), but this did not improve diet diversity from 6 to 24 months. IYCF index decreased throughout follow-up (1 month, 7.8 ± 2.4; 24 months, 5.5 ± 1.8), and pBMI was not associated with IYCF (−0.11 ± 0.13 point, P = 0.4). We conclude that heavier women were not engaging in IYCF behaviours that were distinct from those of normal-weight women from 1 to 24 months post-partum.