This study's aim was to assess the prevalence of hyperlipidemia and its association with birth weight and BMI at 2 years of age and 5 to 6 years of age in full-term-born children. Methods: A population-based, large-scale survey of hyperlipidemia was conducted. Information on 12,701 children aged 5 to 6 years was retrospectively collected from electronic health care records. Results: The rate of high total cholesterol (≥5.18 mmol/L) and/or high triglycerides (≥1.70 mmol/L) was 10.2%. The multivariate-adjusted odds ratios of high total cholesterol and/or triglycerides were 1.33 (1.04-1.69), 1.00, and 0.95 (0.81-1.11) based on birth weight groups (small for gestational age [SGA], appropriate for gestational age, and large for gestational age); 1.06 (0.77-1.45), 1.00, and 0.99 (0.88-1.11) based on BMI groups at around 2 years of age (<10th, 10th to <75th, and ≥75th percentiles); and 1.56 (1.08-2.25), 1.00, and 1.71 (1.44-2.03) based on BMI groups at 5 to 6 years of age (<−2 SD, −2 SD to <2 SD and ≥2 SD), respectively. In the SGA group, hyperlipidemia was not associated with BMI at 2 years of age but was significantly associated with having underweight or obesity at 5 to <6 years of age. Conclusions: SGA infants are at an increased risk for childhood hyperlipidemia, and catch-up growth before the age of 2 years would not affect this risk. For SGA infants, having underweight or obesity after 2 years of age can increase the risk of childhood hyperlipidemia.