Abdominal stab wounds are managed on a selective basis with increasing frequency. Retroperitoneal injuries are more difficult to evaluate; hence wounds to the flank and back pose different considerations. A retrospective review of 108 patients with deep stab wounds of the flank and back was compared with a prospective study of 109 patients selectively managed with similar injuries. Physical examination was accurate in 86% of flank and 88% of back wounds. Local exploration was an effective procedure in differentiating superficial from deep wounds. Peritoneal lavage may be more accurate in flank wounds but is probably less reliable with retroperitoneal injuries. Adjunctive studies are helpful in selected patients. The incidence of negative celiotomies was reduced from 85.2% to 7.3% when the selective approach was adopted. There was no mortality or increased morbidity in the series. Although the risk of retroperitoneal injury is greater with flank and back wounds, frequent examination by the same observer combined with adjunctive studies in selected cases appears to be a safe, reliable method of managing patients with stab wounds of the back and flank.