Gastric ulcers are a common pathological finding at slaughterhouses, with a prevalence of up to 65% in finishers and 35% in nursery pigs. Pigs’ eating behavior is a dynamic process that can be adapted to feed supply, social pen interactions, and disease status. However, evidence addressing the effect of gastric ulceration on feeding behavior in nursery pigs is limited. This study aimed to identify key differences in the diurnal feeding behavior of nursery pigs with no lesions in the pars oesophagea and pigs with severe ulcers in pars oesophagea and fed pelleted feed ad libitum by assessing: (1) differences in the duration of feeding time per visit to the feeder (minutes/visit); (2) differences in the total feeding time per day (minutes/day); (3) differences in the number of feeding visits per day (visits/day). In total, 199 intact male (n = 105) and female (n = 94) nursery pigs were assessed for gastric lesions 6 weeks after weaning observing an overall prevalence of 84%. Based on a gastric health assessment, pigs were characterized as either NLPO “no lesions in the pars oesophagea” (only healthy and parakeratosis scores) or LPO “lesions in the pars oesophagea” (erosions, ulcers, scars, and oesophageal stenosis). The LPO group was further divided into a subgroup: POU “severe ulcers in pars oesophagea” (ulcers with oesophageal stenosis). Diurnal feeding behavior was retrospectively assessed for 30 nursery pigs (15 NLPO and 15 POU) using video recordings from 06:00 AM to 10:00 PM (16 h) for 7 days before the stomachs were collected. The regression model showed that the POU nursery pigs had a tendency to eat for a longer period (+1.3 min) each time they visited the feeder (p = 0.055), but had significantly (p = 0.044) fewer feeding visits (-2.3 visits) during the day compared to NLPO nursery pigs. Both NLPO and POU pigs spent the same amount of feeding time at the feeder per day. Furthermore, it was observed that intact males spent significantly (p = < 0.05) less time per feeding visit to the feeder, had more feeding visits per day, and spent longer feeding time per day compared to females. In conclusion, this study showed that feeding behavior in nursery pigs 6 weeks after weaning was weakly associated with severe gastric ulceration. However, severe gastric ulceration did not have an effect on the total feeding time per day. Moreover, it was found that feeding behavior in nursery pigs is strongly associated with sex.