The occurrence of cancer in 46 couples related only by marriage and treated in a regional hospital is reported. Twenty‐four pairs had tumors of the same histopathologic type. Three couples had the same tumors with similar histology: brain (astrocytoma), urinary bladder (transitional cell carcinoma), and lung (adenocarcinoma). The possible significance of environmental, nutritional, and contamination factors are emphasized, although this is a probably coincidental phenomenon. Copyright © 1990 Wiley‐Liss, Inc., A Wiley Company