An lumbar hernia is a rare clinical disease entity thatarises from the superior or inferior lumbar triangle and presents as a reducible protruding mass in the flank region between twelfth rib and the iliac crest. There are two classifications one classification is a congenital or acquired hernia according to the occurrence timing and the other classification is a superior (Grynfeltt-Lesshaft hernia) or inferior (Petit's hernia) lumbar hernia according to the anatomical location. Approximately 10% of all lumbar hernias are congenital and the vast majority of them are unilateral. We report here a case of a congenital lumbar hernia through the superior lumbar triangle of Grynfeltt-Lesshaft without any other congenital anomalies or complications in a four-month-old male. It was treated successfully with a surgical repair.