The development of the human central nervous system (CNS) begins in the embryonic period and proceeds through a sequence of many intricate processes in the fetal period, as well as postnatally. This results in establishing motor, sensory and cognitive functions as well as behavioral patterns. The diversity and complexity of fetal activity reflects developmental and maturational processes of the CNS. Fetal behavior is defined as any fetal activity observed or recorded with ultrasonic equipment. Nowadays, modern imaging technologies, such as 3D/4D ultrasound, enable prenatal assessment of fetal neurobehavior and developmental processes in different periods of gestation. By applying 3D/4D ultrasound and then interpreting the Kurjak Antenatal Neurodevelopmental Test (KANET) score, it may be possible to make a distinction between normal and abnormal brain development as well as an early identification of children with neurological risk. KANET was developed in 2008 by a Zagreb group of physicians and since then many studies in almost 2000 fetuses have been conducted confirming its reproducibility and usefulness in prenatal assessement of the neurological outcome. The objective of this review is to present the most significant neurodevelopmental events and the relationship between the maturation of the CNS and the emergence of fetal behavior. Considering the importance of prolonged consequences of fetal stress, this review also aims to emphasize how different stimuli, such as pain and changes in the intrauterine environment, induce fetal stress response by accelerating maturation processes. Early detection and prevention of prenatal and perinatal neurological damage, as well as its long-term effects on the children's health, is the main motivation of investigators in the fields of fetal neurophysiology and perinatology.