The current study assessed the child's learning of an object label in two conditions: when its referent was highly similar and when its referent was highly dissimilar to the referent of a known child word. Twenty-two 2-year-old children were taught the name for an object. In a session several days subsequent, they were taught names for two new objects: one which was highly similar and one which was highly dissimilar to the referent of the word learned in the first session (two stimulus sets assured counterbalancing). In this second session, children produced the word with the similar referent more often than the word with the dissimilar referent. In third and fourth sessions (several days later), children continued to show better performance with the similar word in comprehension. These results were interpreted as evidence that young children find it easier to learn a new word when they are able to contrast its referent with that of a word they already know.