Background <p>Peptic gastroduodenal stenosis is a rare but disabling condition causing gastric outlet obstruction. This study aimed to evaluate endoscopic balloon dilation in terms of treatment effectiveness, durability, and identify potential early predictors of unsatisfactory outcomes. </p> Methods <p>We conducted a retrospective cohort study of patients who underwent endoscopic balloon dilation for symptomatic peptic gastroduodenal stenosis at Skåne University Hospital, Lund, Sweden between January 1st, 2003, and December 31st, 2023.</p> Results <p>A total of 58 patients were included, with a median follow-up of 9.58 years [IQR 4.38–14.15]. Endoscopic balloon dilation was successful in 50 patients (86.2%), of whom 7 (14%) experienced symptomatic recurrence that was managed with repeat dilations. Eight patients were classified as non-responders and subsequently underwent surgical treatment. Kaplan–Meier curves identified three distinct response patterns among the responders: fast responders (0–1 months), intermediate responders (1-8 months), and slow responders (8-35 months), roughly corresponding to 1-2 dilations, 3-5 dilations, and 6 or more dilations, respectively. Undergoing more than five dilations had a significantly longer treatment duration and lower treatment effect compared with five or fewer dilations. Moreover, more than five dilations were associated with a significantly increased risk for recurrence (OR = 4.09; 95% CI 1.02–16.40, <i>p</i> = 0.047).</p> Conclusion <p>Most patients with peptic stenosis causing gastric outflow obstruction can be treated successfully with endoscopic balloon dilation alone. More than five dilations seem to be associated with a prolonged treatment period, lower treatment effect and increased risk for recurrence. These findings suggest that reconsideration of treatment strategy could be considered in patients who fail to improve after five dilations. </p>