He made the comments to canon law students attending a course at the Church's highest court, the Roman Rota.
During his address, he revealed he'd previously dismissed a church official for selling annulments for thousands of dollars.
It's thought he was referring to an incident which occurred before he became pope last year.
"We have to be very careful that the procedure does not become a kind of business - and I am not talking about something we know nothing about," he said.
"There have been public scandals. Some time ago, I had to dismiss from a tribunal someone who was saying 'for 10,000 dollars I will do both the civil and the ecclesiastical procedure'."
He went on to seemingly suggest the possibility of 'free annulments' by arguing, "when you attach economic interests to spiritual interests, it is not about God,"
"The mother church has so much generosity it could provide justice free of charge. The Church must be able to say, 'Yes, your marriage is void, or 'No, it is valid"
Annulment was one of the major issues being discussed by cardinals last month at the Vatican Synod on the Family.
Catholics who divorce and remarry without an annulment are not strictly permitted to take Communion.
Some critics have argued that the process of obtaining an annulment is too expensive, making it only available to the wealthy.
Pope Francis seemed to echo these arguments, claiming church tribunals can be "so long and so weighty" that many people became "discouraged" and abandoned the process altogether.