This article assesses the fundamental elements of national and international cartel sanctioning practices from a proportionality perspective under both retributive and consequentialist theories on punishment. It finds that the current framework of setting fines for international cartels fails to ensure proportionate overall punishment. It suggests that, at the least, achieving overall proportionate punishment requires authorities to start considering the retributive and consequentialist objectives already achieved by fines imposed elsewhere for the same overall cartel conduct.