The pattern of operation injuries of the arterial vessels which may occur during hip surgery is illustrated by this summary of our own cases. Injuries of the femoral vessels seem to be preventable if the Hohmann-retractor is carefully placed on the anterior margin of the acetabular rim under digital control. Furthermore drilling damage of the iliac vessel appears to be avoidable. However, the replacement manoeuvre of the artificial acetabulum can be associated with massive bleeding despite greatest care. Under these circumstances immediate surgical intervention through an inguinal retroperitoneal approach is mandatory.