A mixed methods research design, which is a complex approach, combines both quantitative and qualitative data in a single study or succession of studies. This design can be particularly functional for exploring complex research questions that cannot be fully answered by using a single research design. Moreover, a mixed methods design is necessary to examine the relationships between different variables because examining the relationships between diverse variables is not viable just through a single research design. This design is required to complement and cater to the increasingly multifarious requirements of contemporary researchers. This article, which explores and discusses types, purposes, strengths, challenges and criticisms of the mixed methods research design as its objectives, stems from an analysis of some notable works in the field. It is grounded on the secondary qualitative data accumulated in the forms of words from journal articles and books related to the research designs. It assists the novices in the field of research in particular and other researchers in general by providing them with an overview of mixed methods design along with its types, such as convergent parallel, explanatory sequential, exploratory sequential, embedded, transformative and multi-phage designs.