Fetal behavior reflects the activity of the fetal central nervous system (CNS). Insight in fetal behavior is crucial for the understanding of normal fetal well-being and in the evaluation of the possibly compromised fetus. In order to recognize 'behavioral' patterns, linkage of variables (absence of movements, absence of eye movements, heart rate patterns) is obligatory. No single test can predict with certainty if the fetus is compromised and/or what the optimal timing is for the delivery. That is why the study of fetal behavior is very time-consuming. Development of more appropriate methods to analyze fetal behavior should have high priority in clinical perinatology.