A modification of Cohen's (1973) method was used to study responses to patterns of varying complexity in 4-mo.-old infants. Complexity in this context was defined in terms of the number of elements and the degree of internal contour contained in a given pattern. The infants were first presented with small red circles on two trials. This was followed by 16 trials of exposure to either 2 x 2 or 8 x 8 or 24 x 24 small red-circle matrix patterns which again were followed by two further exposures (trials) to the small red circle. Response decrement across trials was measured as a function of fixation, i.e., the duration of time the infant was judged to be looking at the stimulus, and latency, i.e., the time it took the infant to orient toward the stimulus pattern. Infants preferred the more complex patterns. All infants showed decrement in duration of fixation across trials for all three types of pattern. Latency of head turning did not change across trials but differed between pattern types. There were not significant sex differences in habituation rates as measured by duration of fixation and latency.