Effects of chronic maternal food restriction and time of day on maternal and pup behaviors were examined in ovariectomized Sprague-Dawley rats (n = 26). Dams were fed ad lib (AL) or were restricted to 85% (85 AL) or 70% (70 AL) of ad lib intake. Dams and their 5-pup litters were observed for 45 min at night on days 9, 14, and 19 of lactation and during the day on day 14. A novel behavioral instrument was used to observe maternal and pup behaviors. At night, food-restricted animals engaged in more nursing behaviors than AL animals. Differential pup stimuli may account for this difference. AL animals engaged in more nursing behaviors during the day than night, whereas 70 AL animals demonstrated the opposite diurnal pattern. Time of feeding may explain this difference. On the other hand, 85 AL animals behaved similarly during the day and at night. Therefore, alterations in circadian behavior patterns are less pronounced in rats mildly restricted (85 AL) than in rats more food restricted (70 AL).