The relationship between the development of receptive field properties in the stratum griseum superficial of the superior colliculus and the development of a group of visually guided behaviors was studied in kittens 10-39 days of age. Superior colliculus receptive fields in young (10-19 days old) kittens differed from those in adult cats in several ways: many infant colliculus cells ceased responding when repeatedly stimulated more often than cells in adult cats, direction selective responses were absent in young kittens, most cells were driven exclusively by stimuli presented to the contralateral eye, surround inhibition to both moving stimuli and flashing stationary spots was less effective than in the adult, and infant cells were more responsive to a stationary stimulus turned on or off than were adult cells. The immature receptive fields began to acquire more adult receptive field properties by about 15 days of age and continued to change until at least 25 days of age in the case of 4 of the 5 receptive field properties and 35 days of age in the case of the fifth, direction selectivity. Tests of visual and auditory behaviors were made immediately before the animals were prepared for the electrophysiological recordings. Two visually guided behaviors, orienting to a stimulus presented in the visual field and following of a stimulus moved through the field, first could be elicited in the kittens tested at 16 and 18 days of age, respectively. The onset range of these behaviors coincided with the period of rapid change from the immature to the mature state of the receptive fields. Four other visual behaviors - visual cliff judgments, triggered visual placing, obstacle avoidance, and guided visual placing - did not appear until after 25 days of age. The development of these behaviors thus occurred after the superior colliculus receptive fields were essentially complete. Auditory orienting and following responses appeared before visual orienting and following, demonstrating that the capacity to perform these responses was present before a visual stimulus would elicit them. The data of this study are consistent with the suggestion that the maturation of superior colliculus receptive field properties may play an important role in the development of visual orienting and visual following responses in the kitten.