It is a qualitative study with the objective of identifying the man's perception regarding the changes that took place in his marital relationship during the child's breast-feeding. The data were collected through interview with 13 fathers. The results indicate that men develop attitudes and feelings relative to the son and the wife; they recognize that the alterations in their marital relationship are more evident during the first three months of the child's life and they try to understand or to demonstrate indifference towards the changes. Although breastfeeding results in modifications in the spouses' relationship, the fathers do not consider them as something negative in their lives.