Brunner’s gland hamartoma is a rare benign tumour of the duodenum. It was first described by Cruveilhier in 1835. Presently around 200 cases have been reported in literature. No sex predilection is seen. Patients usually present in the fifth to sixth decades of life. They may be clinically silent or may present with variable symptoms and occasionally obstructive symptoms and chronic pancreatitis. Endoscopic presentation can be nodular, polypoid or diffuse glandular proliferation with thickening of duodenal wall and hence can be misdiagnosed as malignancy. We describe a case of duodenal tumor reported outside (on biopsy) as well differentiated adenocarcinoma which out as Brunner gland hamartoma upon complete resection. Brunner gland hamartoma may sometimes have a very unusual presentation. Extensive pre-operative evaluation is necessity to avoid radical surgical procedure.