This quasi-experimental study examined expressive vocabulary outcomes for Parent-Child Home Program (PCHP) toddlers, after one year of home-visiting services. First, this study applied Rasch modelling to establish the construct validity and reliability of a widely used expressive vocabulary measure, as modified for a sample of ethnic and linguistic minority toddlers. Following, between-groups differences in expressive vocabulary were examined for PCHP children and comparison children who were similar in socio-economic status, age, and neighbourhood residence. Indication of larger expressive vocabularies for PCHP children, relative to comparison children, reflected the benefits of one year of home visiting. Effect sizes for English- and Spanish-speaking subsamples of PCHP and comparison children showed that Spanish-speaking children experienced the greatest growth. Although promising findings emerged, this study highlights methodological limitations that should be improved in order to advance empirical demonstration of the impact of home visiting on children's expressive vocabulary outcomes. (author abstract)