In the picture-word interference paradigm, participants name a picture while ignoring a distractor word. The time it takes to name the target picture is affected (among specific properties of the picture and the word) by the relationship between the naming response and the distractor stimulus. Picture naming latencies are faster in the context of distractor words that are semantically related to the target picture (semantic facilitation). However, naming latencies are slower in the context of distractor words that are semantic coordinates of the naming response (semantic interference). This review discusses the implications of the semantic effects (facilitation and interference) in the picture-word interference paradigm for the theory of lexical selection by competition.