We consider bivariate survival problems in which interest is in the conditi
onal distribution of one survival variable given an uncensored observation
of the other. The work is motivated by an analysis of time to cancer diagno
sis then subsequent survival amongst a group of organ transplant recipients
. The effect of conditioning is illustrated for five standard bivariate mod
els. The consequences of adopting a misspecified marginal approach in which
the conditioning variable is considered to be a fixed covariate are invest
igated. Copyright (C) 2000 John Wiley & Sons, Ltd.