Using hospital discharge data from the counties in Northern Denmark and the Danish Cancer Registry, we examined the trend in the prevalence of breast-conserving surgery (BCS) to treat primary breast cancer from 1982 through 2002, with an emphasis on publications that may have influenced surgical practice in Denmark. Overall, the prevalence of BCS increased from less than 1% of breast cancer operations in 1982 to approximately 25% by 2002. The rise in prevalence was most pronounced for the treatment of young women and women with early-stage breast cancer. Of three pivotal clinical trials, the most significant trigger of the upward trend appeared to be a study conducted by the Danish Breast Cancer Cooperative Group, published in 1988. After 1988, there was a steep rise in the prevalence of BCS. By 2002, BCS prevalence appeared to reach a threshold at 25% of breast cancer operations, seemingly defined by the proportion of new breast cancer cases who are good candidates for BCS.