Antibiotics in the environment provoke serious consequences on living beings and can be effectively remediated by prominent advanced oxidation process. In this study, electrochemical advanced oxidation treatment in a lab-scale reactor for the degradation of florfenicol (FLO) was studied with the aid of boron-doped diamond anode (BDD). The results exhibited that the FLO degradation follows pseudo-first-order kinetics. As the current intensity rose from 60 mA to 250 mA, the FLO removal efficiency increased and the corresponding reaction rate constant increased from 0.0213 to 0.0343 min⁻¹, which was likely due to the more efficient participation of free hydroxyl radical (^•OH) generated at the BDD anode. Faster degradation and higher mineralization of electrolyzed FLO solution were achieved at higher current intensity as well as in higher SO₄²⁻ concentration medium, as a consequence of catalytic participation of oxidants (free ^•OH as well as sulfate radical (SO₄^•−) and persulfate (S₂O₈²⁻)). The increase in FLO concentration from 30 to 50 mg L⁻¹ resulted in a reaction rate constant decrease (from 0.0235 to 0.0178 min⁻¹). Eight transformation by-products (m/z = 372.99, 359.8, 338.0, 324.04, 199.00, 185.02, 168.99 and 78.989) and three inorganic ions (NO₃⁻, Cl⁻ and F⁻) were analyzed by UPLC‒Q‒TOF‒MS/MS and Ion‒chromatography, respectively. The Vibrio fischeri bioluminescence inhibition revealed an increase of toxicity during the electrochemical oxidation that could be attributed mostly to the generated organic chlorinated by-products (m/z = 372.99, 359.8) and inorganic species (ClO₂⁻ and ClO₃⁻).