Ewing sarcoma usually develops in the second decade of life as a primary osseous malignancy. An extraskeletal primary source of this condition from the lung parenchyma is extremely uncommon. We report the case of a 33-year old man with primary Ewing sarcoma of the lung diagnosed upon postsurgical histological examination. Initially presenting with unilateral pleural effusion, our patient underwent various investigations before final diagnosis. This case report reviews the available literature of similarly reported cases and discusses the current developments on managing this rare and aggressive disease. As a supplementary learning point, this case reminds us always to consider unusual possibilities and seek further sub-specialist opinion when presented with unresolved clinical and radiological abnormalities that require further exploring beyond the primary line of investigations and treatment.