Infancy is characterized by a significant increase of motor abilities. Early diagnosis and therapy of infants with developmental disorders is an important topic, considering the number of children at risk of improper development. The survival rate of premature infants and high risk infants has increased, however, premature infants are at a higher risk of developmental delays and physical disabilities. Motor development in infancy can be assessed in various ways. This article presents information on developmental processes in the human brain as well as typical and atypical motor development and factors conditioning motor development in infants. In addition, selected assessment methods of infant motor development were characterized and evaluated.