Recognizing familiar words quickly and accurately facilitates learning new words, as well as other aspects of language acquisition. This study used the visual world paradigm with semantic and phonological competitors to study lexical processing efficiency in 2- to 5-year-old children. Experiment 1 found this paradigm was sensitive to vocabulary-size differences. Experiment 2 included a more diverse group of children who were tested in their native dialect (either African American English or mainstream American English). No effect of stimulus dialect was observed. The results showed that vocabulary size was a better predictor of eye gaze patterns than was maternal education, but that maternal education level had a moderating effect; as maternal education level increased, vocabulary size was less predictive of lexical processing efficiency.