<p>Antibiotics pose a challenge to conventional wastewater treatment processes, which generally have limited capacity to remove them. High and indiscriminate consumption combined with improper disposal are how these compounds reach the environment. Anaerobic digestion (AD) is a biological process that can be used as an alternative for removing antibiotics from wastewater. In addition to eliminating the compounds, other advantages of AD are the recovery of biogas produced during the process for energy purposes, along with a reduction in greenhouse gas emissions into the atmosphere. Despite its potential, there is still a need for further studies on the removal of antibiotics through biological processes such as AD. The objective of this study was to evaluate the AD for the degradation of the antibiotics sulfamethoxazole (SMX) and norfloxacin (NOR). Batch reactors were used under controlled operating conditions. Reactors containing different concentrations of antibiotics, as well as mixed antibiotics, were evaluated. Operational parameters of cumulative biogas production, biochemical methane potential, percentage of methane in biogas, volatile fatty acids, chemical oxygen demand, and removal of antibiotics from the aqueous phase were analyzed. Results indicated that the type and concentration of antibiotics influenced cumulative biogas production. The highest values for cumulative biogas production and biochemical methane potential were for reactors with mixed antibiotics. The percentage of methane in biogas remained within the range considered normal for all samples. The concentration of SMX did not influence the removal rate, while for NOR, a reduction in the removal rate from the aqueous phase was observed with increasing concentration.</p> Graphical Abstract <p></p>