Objective: Arsenic, one of the major natural as well as anthropogenic pollutant produces biochemical changes in the organs of animals due to its potential toxicity. Arsenic is toxic to fish and may be taken through gills and skin. In the current work, arsenic trioxide-treated fishes were prescribed with potentized homoeopathic drug, ars alb 30C, and ars alb 200C. The biochemical contents in exposed gill tissues of zebrafish (Danio rerio) were analysed using Fourier transform infrared spectroscopy (FTIR).Methods: The acclimatised fish were treated with arsenic trioxide and LC50 was calculated. Along with arsenic trioxide, the homoeopathic drug ars alb 30C and ars alb 200C were given three drops per litre. After a period of 7 and 14 d, the gills of exposed fish were dissected. The samples were lyophilized and analysed in FTIR.Results: In arsenic exposed fish, the amine N-H stretch was different when compared to the control and the treated different potencies of ars alb 30C and 200C respectively at 7days. Whereas at 14 d the arsenic exposed fish the amine N-H stretch was drastically reduced. Notably, in treating different potencies of ars alb 30C and 200C, the amine N-H stretch was increased.Conclusion: It was found that the higher the potency that is ars alb 200C was more effective against Arsenic toxicity. It shows higher dilution may be efficacious