Fluoxetine is an antidepressant used to treat several conditions including postpartum depression. This disease causes cognitive, emotional, behavioral and physical changes, negatively affecting the mother, child and family life. However, fluoxetine is excreted in breast milk, causing short and long-term effects on children who were exposed to the drug during lactation, so studies that seek to uncover these consequences are needed. Thus, the aim of this study was to evaluate the effects of fluoxetine on rat milk’s properties and on the physical and neurobehavioral development of the offspring. Lactating rats were divided into 4 groups: control group and three experimental groups, which were treated with different doses of fluoxetine (1, 10 and 20 mg/kg) during the lactation. Dams body weight and milk properties were measured, as well as offspring’s physical and neurobehavioral development. Results showed that the use of fluoxetine during lactation decreased dam’s body weight and alters milk’s properties, leading to implications on the offspring growth until adulthood. Therefore, the use of fluoxetine during lactation needs to be cautiously evaluated, with the benefits to the mothers and the associated risk to the offspring carefully balance.