A system and method to trim reference levels in a resistive memory is disclosed. In a particular embodiment, a resistive memory includes multiple sets of reference cells. The resistive memory also includes a reference resistance measurement circuit. A first set of reference cells is accessible by the reference resistance measurement circuit to measure a first effective reference resistance corresponding to the first set of reference cells. A second set of reference cells is accessible by the reference resistance measurement circuit to measure a second effective reference resistance corresponding to the second set of reference cells. The resistive memory also includes a trimming circuit configured to set a reference resistance based on the measured first effective resistance and the measured second effective resistance.