The complexity of the metastatic cascade has led to the development of a plethora of 2-and 3-dimensional in vitro assays to model the various steps of metastasis under a more controlled environment. These assays have been invaluable in cancer research not only as tools to delineate the molecular events that underpin metastasis but also to enable drug screens and validation of therapeutic targets. Here we review the advantages and limitations of current in vitro platforms used to investigate metastasis. In light of the overwhelming evidence showing that 3-dimentional culture systems better mimic the tumor microenvironment and therapeutic response in vivo, recent advances made toward the development of 3-dimensional culture systems and their applications are discussed in more detail. Relevant information on protocols and resources available to support scientists with an interest in metastasis research is also provided.