Cognitive abilities of low birth weight infants (1500-2000 grams) were compared to that of normal controls (2500-3500 grams) in tasks using recognition and recall measures. Three groups of infants at different ages: group I (4-6 months), group II (7-9 months), and group III (10-12 months), each consisting of 30 low birth weight and 30 controls par- ticipated in the study. Infants of group I were tested for fundamental sensory abilities such as visual recognition memory, auditory and tactile preferences. Infants of group II were tested on tasks of imitation and object permanence, both requiring some form of rep- resentation and recall abilities. Infants of group III were tested on inter-modal matching, which required ability for sen- sory integration. Results indicate that the low birth weight infants performed poorly on all tasks except tactile preferences. They seem to lag behind the normal infants in general, and in some tasks by approximately four weeks. This suggests the importance of brain maturation for the performance of these tasks since previous studies indicate a relationship between birth weight and cognitive performance. Thus intra-uterine growth retardation (IGUR) consequently delays development and is an impor- tant determinant of low birth weight.