This article investigated the risk of household food insecurity and reported fair or poor health among very young children who were US citizens and whose mothers were immigrants compared with those whose mothers had been born in the United States.  In a sample of 19,275 mothers (7,216 whom were immigrants) the risk of fair or poor health was higher among children of recent immigrants than among children of US-born mothers.  Overall, household food insecurity increased the risk of fair or poor child health and mediated the association between immigrant status and poor child health.  Policy interventions addressing food insecurity in immigrant households may promote child health.