There are growing concerns about the effects of poverty on children's health, but few studies have examined how the long-term experience of poverty affects the general health of children. We sought to investigate the relationship between children's poverty experience from birth to school age and their general health status. Data from the Taiwan Birth Cohort Study (TBCS), a nationally representative sample of 17,853 children born in 2005 were used. Mother-rated health of children at age 8 was assessed. We used logistic regression to examine how the duration and timing of child poverty are related to children's general health, controlling for child and maternal characteristics. Of the 17,853 cohort members, 23.6% experienced early poverty (persistent, 5.9%; occasional, 17.7%) before age 5, and 11.4% experienced concurrent poverty at the age of 8. Children born into poverty and remaining poor were more likely to have poor health than those who were never poor. Early poverty (persistent poverty: odds ratio (OR) = 1.50; 95% confidence interval (CI) 1.27-1.78; occasional poverty: OR = 1.25; 95% CI 1.12-1.39) was more detrimental to children's general health than concurrent poverty (OR = 1.23; 95% CI 1.09-1.40). A long-lasting gradient effect of early poverty on the general health of children was detected, suggesting an urgent need to prevent children from growing up in persistent poverty.