Previous research has indicated that the risk conferred by men's Type A versus B behavior depends, in part, on the personality characteristics of their spouses. In the present study of 60 married couples, we found that couples consisting of two Structured Interview-defined Type A's showed a larger increase in hostile/dominant behavior during discussions of marital conflicts than did couples consisting of two Type B's or a Type A husband and a Type B wife. Couples consisting of a Type B husband and a Type A wife displayed an intermediate level of hostile dominance. These results are consistent with previous speculations about interpersonal dynamics in Type A behavior and interaction patterns which might underlie spouse effects on Type A behavior and coronary risk.