Two hundred thirteen patients with stab wounds to the lower part of the chest and abdomen were reviewed to determine if a lavage RBC count of 100,000/cu mm was a reasonable figure to permit prompt recognition of injury and to minimize the number of negative operative procedures. There were four (1.9%) false-positive and nine (4.2%) false-negative lavages. Three patients (1.4%) had complications due to delayed operation, including one death (0.47%). Two patients (0.9%) had hollow viscus injuries; neither involved the colon. Three of the nine patients with injuries had cell counts of less than 1,000/cu mm. The negative cellotomy rate was 4.2%. It was concluded that the number of missed injuries, delayed operative procedures, and complications was sufficiently low enough to continue recommending 100,000 RBCs per cubic millimeter as a safe number to use as an indication for operation.