Assessing vocabulary knowledge is an important part of establishing language proficiency in bilingual children. The crosslinguistic lexical tasks (CLTs) provide a framework for testing vocabulary development in three-to-six year-olds using a standard procedure and comparable items for multiple languages. This study describes the development of the Irish CLTs to test receptive and expressive vocabulary for nouns and verbs. The test was then used in a pilot study to measure the vocabulary development in both Irish and English of 41 bilingual children attending Irish-immersion education in an Irish-speaking region of Ireland. The results showed that, as expected, children found lexical comprehension to be easier than production, and nouns easier than verbs. As a group, those from Irish dominant homes performed similarly on both the Irish and English versions of the CLTs, but those from bilingual and English-dominant homes performed significantly better on the English version. The amount of home-language exposure to Irish and English showed advantages on production tasks in each language. However, all groups performed relatively poorly on the production and comprehension of Irish verbs. We explore the findings in relation to the importance of language exposure in a minority language context.