© 2021 Taylor & Francis Group, LLC.The presence of pharmaceutical in waters has raised the challenge of antimicrobial resistance. This paper presents a study on the adsorption of Oxytetracycline (OTC) from an aqueous using a modified Iron Oxide (Fe3O4) which was modified with Polyethyleneimine (PEI) polymer and coated with Polyoxyethylene Sorbitan Trioleate (Tween 85) surfactant. The adsorption performance was examined the effect of pH, temperature, contact time, adsorbent dosage and drug concentration based on batch experiments. High OTC removal rates of about 98% for the 1:2 with Tween 85 were obtained at pH 4, similar removal efficiency was obtained for the 1:2 Tween 85-free at pH 3. Also, it was seen that the adsorption process was a physical and exothermic process in terms of thermodynamics. The adsorption can be well explained by Freundlich isotherm model. The results demonstrate that the modified magnetic material, with low concentration of 0.025 g, have great potential to capture OTC. Also, qm value (277.8 mg/g) of the adsorbent shows its great potential and the adsorbent reaches its maximum capacity in a short time (~10 minutes).The experimental results reveal that Fe3O4@PEI®Tween 85 would be a promising solution with high removal efficiency and low-cost adsorbent for water matrices protection.