Zinc (Zn) is an essential micronutrient required for multiple biological functions and used at therapeutic doses to reduce diarrhea and increase feed intake and performance in piglets. However, high doses of Zn in the diet are associated with heavy metal soil contamination and antimicrobial resistance which it may indicate the need to restrict or modify the therapeutic use of ZnO in piglets. A study was performed to assess how growth, mortality and Zn serum concentration change when Zn therapeutic is removed. A total of 400 weaned piglets [Pietrain × (Landrace × Large White)] were assigned to 2 different dietary strategies: Therapeutic (T diet, 122ppm of Zn as nutrient and 2,480ppm Zn as ZnO, 11.0 MJ/kg NE, 20.2% CP, 1.37 Lys) and Nutritional, in which the diet was formulated with a lower CP content, (N diet with 125ppm Zn as nutrient, 10.6 MJ/kg NE, 16.5% CP, 1.20 Lys) during the nursery period (0 to 35d). On d 35, piglets were moved to the growing barns and fed the same diet (110 ppm Zn, 10.0 MJ/kg NE, 16.0% CP, 0.95 Lys). Piglets were weighted on d 0, 14, 35 and 57 and mortality was registered. Blood samples were obtained from 15 piglets per group to analyze Zn status on d 0, 7, 35 and 49 post-weaning. All studied parameters were analyzed with one-way ANOVA taking into account the experimental treatment as main factor with α level of 0.05. No differences were observed on growth during the whole period, but higher mortality was observed in the N group compared with the T group. A temporary decrease of Zn serum concentration was observed after weaning in pigs fed the N diet (0.95, 0.67 and 1.07 mg/L on d 0, 7 and 35, respectively), whereas T piglets increased Zn concentration (0.95, 1.20, 1.31 mg/L, on d 0, 7 and 35, respectively; P < 0.001). When T piglets were moved to the growing barns showed a decrease of Zn concentration (1.05 mg/L on d 49) while the N piglets showed a recuperation of Zn status to physiological levels (1.20 mg/L on d 49). These results might indicate a drop of blood Zn levels and an increase on mortality when therapeutic doses of Zn are removed and low CP diet is used, suggesting the need of using new, more efficient Zn compounds.