The Infant Motor Profile (IMP) is an instrument to assess motor development in infancy. It is a video-based assessment for infants aged 3 to 18 months, or rather until the age of walking independently for a few months. It is based on a video of about 15 minutes of spontaneous motor behaviour in supine, prone, sitting, standing, walking and during reaching and grasping – depending on the age of the infant. The IMP does not only include information about the infant’s motor achievement but also information about the way in which the infant accomplishes his/her achievements. The qualitative aspects of the assessment are based on the principles of the Neuronal Group Selection Theory (NGST). This means that key parameters in IMP assessment are the size of the infant’s motor repertoire (sufficiently variable or not; 25 items) and the infant’s ability to make an adaptive selection out of his/her repertoire (15 items). Other domains are performance (23 items), symmetry (10 items) and fluency (7 items). Studies indicate that the IMP is an instrument with good reliability and promising validity.