The present series of experiments explores the interaction between retroactive interference and cue competition in human contingency learning. The results of two experiments show that a cue that has been exposed to a cue competition treatment (overshadowing) loses part of its ability to retroactively interfere with responding to a different cue that was paired with the same outcome. These results pose problems for associative models of contingency learning and are also difficult to explain in terms of current theories of causal reasoning. Additionally, it is proposed that in light of the interaction between interference and cue competition, interference could be used as an indirect measure for the study of cue competition effects. (Contains 2 tables and 2 figures.)