Background: Incomplete duodenal obstruction accounts for only 2% of all duodenal anomalies. Because of its rarity those patients can be easily misdiagnosed and delayed in their presentation. The aim of this study is to assess these rare conditions with its delayed presentation and their outcome. Methods: Nineteen cases presented with incomplete duodenal obstruction during the period from January 2010 to January 2015. Cases with complete duodenal obstruction were excluded from the study. None of those nineteen cases were diagnosed antenatal. The assessment parameters were; their provisional preoperative diagnosis, definite post-operative diagnosis, complications related to miss or delayed diagnosis and their final outcome. Results: All nineteen cases except six presented with persistent or recurrent attacks of vomiting since birth. Their provisional clinical diagnosis was malrotation in 9 cases, duodenal stenosis in 6 cases and atresia in 4. Their final diagnosis was; duodenal stenosis or web in fifteen cases, preduodenal portal vein in two, superior mesenteric artery syndrome in one case and duodenal hematoma in one case. The cause of misdiagnosis was related to lack of experience that leads to unsuccessful exploration or delayed surgical intervention. The post-operative complications occurred in 26.3% of cases. No mortality encountered in this study. Conclusions: Rare causes of incomplete duodenal obstruction should be looked for routinely to avoid delayed presentation, misdiagnosis and unsuccessful exploration.