Purpose: Our objective was to replicate previous cross-linguistic findings by comparing Portuguese and U.S. children with respect to (a) effects of language, gender, and age on vocabulary size; (b) lexical composition; and (c) late talking. Method: We used the Language Development Survey (LDS; Rescorla, 1989) with children (18-35 months) learning European Portuguese (n = 181) and English (n = 206). Results: In both languages, girls had higher vocabulary scores than boys and vocabulary scores increased with age. Portuguese LDS scores were significantly lower than English scores, but the effect size was small. Cross-linguistic concordance of percentage use scores yielded a Q correlation of.50, with 64 of the “top 100” words being exact matches. Cross-linguistic concordance was highest for the youngest age group. In both languages, vocabulary composition in late talkers (children ≥ 24 months with < 50 words) was highly correlated with composition in vocabulary size-matched younger children. Conclusions: Results replicated previous Greek, Korean, and Italian LDS studies. The early lexicons of typical talkers and late talkers contained many of the same words, indicating considerable universality and suggesting good targets for clinical intervention.