Low back pain (LBP) in young adults is a common condition that needs to be appropriately examined in cases of refractory to classic treatment strategies. We present two cases of chronic LBP with challenging diagnosis and treatment refractoriness. The first case corresponds to a young lady that has been treated mistakenly with an anti-tumor necrosis factor because her treating doctors diagnosed unilateral sacroiliitis which turned out to be a magnetic resonance imaging (MRI) artifact (partial volume artifact). The second case is about another young lady with chronic LBP that did not respond to the classic treatment with non-steroidal anti-inflammatory drugs. Both cases have been diagnosed as having Bertolotti syndrome. Bertolotti syndrome is an anatomical abnormality consisting of partial unilateral or bilateral fusion of the transverse process of the lowest lumbar vertebrae to the sacrum. The presentation of both cases highlights the importance of a minute history taking and clinical examination especially in young patients with chronic LBP.