The present study shows an interesting effect of soil enrichment with 5% sewage sludge on the behavior of young olive trees. In fact, a significant improvement in the length of the main stem is observed. By providing nutrients, the sewage sludge (5%) also increased the leaf nitrogen content. However, doses of 10 and 15% increase stress indicators in terms of malondialdehyde content and loss of electrolytes, which could be explained by the important level of salts and organic pollutants in sewage sludge.