This investigation examined the ability of 44 preschool children to acquire novel words embedded in storybook contexts. Previous investigations of word learning have typically consisted of novel words for which synonyms exist. It is argued that the acquisition of unfamiliar words that refer to existing concepts that already have labels is not necessarily the same process as the acquisition of legitimately new words for novel referents. Storybook conditions were designed to provide equivalent opportunity for exposure to the target words in two different contexts. All target words consisted of single-syllable, high phonotactic probability sound sequences. This investigation was designed for several purposes: (1) to examine children's receptive identification of novel words following brief exposure (fast mapping); (2) to identify possible differences in acquisition of nouns and verbs; and (3) to determine if the rate of acquisition of novel words significantly differs by the context of presentation. All children identified novel words following exposure through book reading, preferring nouns over verbs. Participants in one version of the story acquired a significantly greater total number of words. Verb learning did not differ significantly between the storybook conditions. (Contains 4 tables and 1 figure.)