In studies assessing sustained attention, performance is often characterized by a decline in function over time. This response pattern, termed the vigilance decrement, is sensitive to manipulations affecting task difficulty, and reversal with nicotine. The choice reaction time task (CRTT) has been described as a test of sustained attention in rats. However, studies describing vigilance decrements and effects of nicotine in this task are scarce. We manipulated the CRTT to determine under which conditions a replicable vigilance decrement could be observed, and sought to determine whether this change was sensitive to nicotine administration. In the ten rats, dose-responses were then derived for nicotine (0.01-0.3 mg/kg). Decreasing the presentation rate of stimulus by prolonging the inter-trial intervals resulted in a decline in the performance speed and increase in omission errors. Nicotine administration reversed the performance decrement. These results serve to validate further the CRTT as a measure of sustained attention.