1. The zinc status of surgical patients with and without gastrointestinal cancer was studied.
2. Plasma zinc was lowest in patients with cancer concurrent with depressed plasma albumin concentrations.
3. Polymorphonuclear cell zinc was decreased in both patient groups and correlated strongly with abdominal muscle zinc (r = 0.89, P < 0.001).
4. Mononuclear cell and total leucocyte zinc were similar to control values in both groups of patients. Total leucocyte, but not mononuclear cell, zinc correlated weakly with muscle zinc (r = 0.48, P < 0.05).
5. The results suggest that polymorphonuclear cell zinc may be better than leucocyte zinc in assessing zinc status and that some surgical patients may be zinc-depleted. The presence of gastrointestinal cancer did not influence the zinc status.