Despite the central role culture plays in racial and ethnic disparities in mental health among ethnic minority and immigrant children and families, existing measures of engagement in mental health services have failed to integrate culturally specific factors that shape these families' engagement with mental health services. To illustrate this gap, the authors systematically review 119 existing instruments that measure the multi-dimensional and developmental process of engagement for ethnic minority and immigrant children and families. The review is anchored in a new integrated conceptualization of engagement, the culturally infused engagement model. The review assesses culturally relevant cognitive, attitudinal, and behavioral mechanisms of engagement from the stages of problem recognition and help seeking to treatment participation that can help illuminate the gaps. Existing measures examined four central domains pertinent to the process of engagement for ethnic minority and immigrant children and families: (a) expressions of mental distress and illness, (b) causal explanations of mental distress and illness, (c) beliefs about mental distress and illness, and (d) beliefs and experiences of seeking help. The findings highlight the variety of tools that are used to measure behavioral and attitudinal dimensions of engagement, showing the limitations of their application for ethnic minority and immigrant children and families. The review proposes directions for promising research methodologies to help intervention scientists and clinicians improve engagement and service delivery and reduce disparities among ethnic minority and immigrant children and families at large, and recommends practical applications for training, program planning, and policymaking.