The Italy international faces a four-week spell on the sidelines as he will undergo surgery on his left knee on Wednesday.
The 31-year-old had been complaining about discomfort in his left knee for a while and underwent further examination on Monday to determine the extent of the injury, leading to the decision to go under the knife this week.
"Christian Maggio will undergo surgery on Wednesday and will be back after the break for international games," an official Napoli statement reads.
Maggio will consequently miss the Serie A games against Sassuolo, Genoa and Livorno, while he will also be forced to watch the Champions League match versus Arsenal from the stands.
The Italy international has made three official appearances for Napoli so far this term.