In this series, we compared the prenatal risk factors and perinatal complications of small-for-gestational-age (SGA) and appropriate-for-gestational-age (AGA) babies systemically through a case-controlled study. A total of 115 SGA babies were retrospectively compared with 115 AGA matched pairs at the National Cheng Kung University Hospital. We analyzed the prenatal risk factors, signs of fetal distress and perinatal outcome between these two groups. Univariate analysis showed significant differences for the following items: 1) maternal risk factors, 2) fetal risk factors, 3) presence of prenatal risk factors, 4) abnormal fetal heart rate tracings, 5) low one-minute Apgar scores, 6) low five-minute Apgar scores, 7) thick meconium staining, 8) presence of fetal distress, 9) pediatric ICU care, and 10) presence of perinatal complications. Multivariate logistic regression showed that maternal hypertension and fetal anomaly were statistically significant risk factors associated with SGA in this series. In conclusion, SGA babies demonstrate higher frequencies of maternal and fetal risk factors, signs of fetal distress and perinatal complications than AGA babies.