The trigger logic for the Collider Detector Facility (CDF) at Fermilab is described. An analog/digital system constructs triggers based on clusters of energy in the calorimetry. These triggers are then combined with signals from the muon and central tracking systems to make a global trigger. Two levels of trigger logic have been implemented: a 'Level 1' trigger which is dead-timeless, and a more sophisticated Level 2 trigger. The rejection factor provided by these two systems will be 103 - 104.