In the US catfish industry, infectious diseases cause significant revenue and financial loss, with millions of fish affected annually. Chronic stress and suboptimal rearing conditions increase disease susceptibility, causing millions in lost revenue. Historically, chemical s and drugs have been used to treat bacterial diseases. Nevertheless, these treatments are becoming more restricted since they present numerous side effects on the environment and health safety . Tryptophan is an essential amino acid for fish, and previous studies have shown that tryptophan could improve the immune response in fish. In this research, we wanted to investigate if tryptophan could increase the immunity and disease resistance in catfish , Ictalurus punctatus, raised in an aquaculture setting . We had five different groups for the experiment : (1) control group; (2) stressed group; (3) stressed group challenged with virulent Aeromonas hydrophila (vAh; ML09-119); (4) stressed group treated with tryptophan; and (5) stressed group treated with tryptophan and challenged with vAh . After 72 hours post-infection, we observed a significant reduction in the mortality rate in the stressed group treated with tryptophan and challenged with vAh compared to the stress group not treated with tryptophan and challenged with vAh . Based on this preliminary study, we can infer that tryptophan has a considerable effect in reducing fish susceptibility to mortality caused by bacterial disease in the face of environmental stressors. The results from this study could have a significant impact on farming practices in the catfish industry.