Aquaculture production has intensified over the recent years in Uganda. However, the industry is threatened by emergence and re-emergence of disease incidences leading to massive mortalities particularly in fish hatcheries and cages. Farmers use antibiotics and chemicals in disease prevention and management, but these chemicals have negative impact to the environment, aquatic life and human health through development and transfer of drug resistant strains. Therefore, this study was conducted to investigate the effect of plant extracts as growth promoters for farmed Nile tilapia (O. niloticus). Results showed increase in weight of fish and good health. High mean weight gain was observed at 0% treatment, however, survival was highest at inclusion of 0.5%. Use of plant extracts have a potential to improve growth of farmed fish while saving the environment and safety of consumers.