The process of migration has resulted in population growth and contributed to the transformation of New Zealand. Migrant and refugee children face many adjustment factors and their ease in resettling in New Zealand is largely dependent on their ability to learn English. Migration stress, change, trauma and loss may result in psychological difficulties which in turn may affect their resettling and learning. The Ministry of Education and other professionals work together to enhance the quality of their service provision to facilitate easier adjustment, resettlement and effective learning for these children. An adequate assessment battery for speech language therapists to assess migrant and refugee children, is presently lacking in New Zealand. Therapists currently use various assessments, with the assistance of interpreters. The New Zealand Speech Therapists’ Association (NZSTA), in accordance with speech therapists in Group Special Education (GSE), strongly supports the need for research with these groups and the development of an appropriate assessment battery. This exploratory study aimed to determine an assessment battery for use in examining English language acquisition in refugee and migrant children and to highlight the benefit of using measurement tools that determine incremental change over time in contrast to the use of monolingual psychometric tests. The study explored a selected assessment battery and gathered data in five main focus areas, namely: cognition, language, trauma, classroom behaviour, developmental and birth information. Eligible children were those who did not have physiologically - impaired cognitive abilities. Eight cases, four refugee and four migrant students, were selected by convenience sampling. All participants were children selected from primary school 1 (three refugees and three migrants) and primary school 2 (one refugee and one migrant) primary schools, aged approximately (5-8 years). Participants included four male and four females, refugee and migrant children, and those with both high and low English ability. Based on the study’s results, recommendations were made to refine the test battery, which included test modification. For example, the use of the trauma measurement tool only if there is prior evidence of trauma, the inclusion of a larger test population who have a common primary language to allow for cost effective interpreter use and to also allow for generalisations to be made, the inclusion of an assessment of the children’s primary language in order to determine the relationship, development and acquisition of the child’s second language with reference to his/her development and skills in his native language. All of the refugee children and 3 migrant children displayed slower processing time during the administration of the tests. Migrant parents were quicker in test completion as compared to refugee parents. They displayed differences in family size, contact with extended family, socioeconomic status and educational level. Migrant children produced sentences that included correct word order and sequence whilst refugee children produced sentences that lacked adequate word order or lacked articles and determiners. The study found the proposed test battery was an effective choice for use in the assessment of both migrant and refugee children, as the battery allows for dynamic assessment of children from diverse groups and this proved to be an unbiased means of assessing their English language and cognitive skills. Recommendations are made for future, more-extensive research. These findings provide information about appropriate and reliable language acquisition tests that measure incremental change with time. This study will contribute to a developing knowledge base for speech-language therapists who work with migrant or refugee children. Effective assessment on which to base tailored language programmes will assist them to optimise their experience in New Zealand schools and enhance their English language skills.