Primary osteosarcoma of the spine is indeed rare and onlyseveral sporadic cases have been reported. It tends to occurin a slightly older age group than those with appendicularskeleton tumours. We present here an unusual case ofaggressive lumbosacral osteosarcoma in a young teenagercomplicated by extensive dural spread, skip lesions andintravascular extension. Although a histopathologicalexamination is mandatory to establish the diagnosis, thiscase emphasises the need of imaging to ascertain the fullextent of disease spread especially in deciding the type oftreatment to be instituted and to evaluate the response tothe treatment.