Sunflower residues are a prominent substrate of renewable source for biogas production during anaerobic digestion (AD). However, due to its recalcitrant structure, pretreatment is necessary to increase its biodegradability. The objective of the present work was to evaluate the effect of the NaOH pretreatment on the methane production from sunflower residues. The residues were separated into stalks and heads after seed removal. It was observed that pretreatment caused an increase in the biochemical methane potential (BMP) during batch tests, but a decrease was recorded during continuous experiments.