The present study aimed to identify and measure the relationship between malnutrition and psychosocial care in the second year of life. A case-control study compared 101 malnourished 12-23-month-old children (weight-for-age < 5th percentile, WHO/NCHS) to 200 well-nourished children (weight-for-age > 25th percentile) for exposure to various maternal behaviors related to psychosocial care. A psychosocial care score was constructed, based on the number of desirable maternal behaviors that were absent (the higher the score, the worse the quality of childcare). The association was modified by per capita family income. After adjusting for possible confounders, children from higher-income households showed no association between psychosocial care and malnutrition. For children from lower-income households, worse psychosocial care doubled the risk of malnutrition (OR = 7.26; 95%CI: 2.42-21.82) compared to low income alone (OR = 3.08; 95%CI: 1.28-7.42).