This research article published by Springer Nature Switzerland AG., 2020Banana leaves wastes (BL) were subjected to fungal treatment using Pleurotus ostreatus to produce edible mushrooms and biogas in the anaerobic digestion process. Effects of fungal treatment on mushrooms production, lignin degradation, trace elements compositions and biogas yield during the anaerobic digestion process were evaluated. Treatment with P.ostreatus for 36 d resulted in the production of 181 ± 19 g of edible mushrooms per 2 kg of BL with biological efficiency of 37 ± 4%. Lignin concentration in fungal treated BL decreased by 10% indicating an improvement on its digestibility. Important trace elements (Fe, Mn, Mo, Co and Ni) necessary for the improvement of the anaerobic digestion process were also significantly reduced (P < 0.05) during the fungal treatment process. The biogas yield for the fungal treated BL was 282 mL g−1 VS−1 of which this study suggests that could be improved through trace element supplementation during the anaerobic digestion process.