This chapter describes current research and practice for conducting a child custody assessment. Although not intended as an in-depth discussion of all relevant issues in the arena, this chapter will direct readers to published, peer-reviewed literature, empirical research, professional practice guidelines, and current models that will provide a greater understanding of relevant topics. The chapter includes discussions of bias, best interests standards, procedures for conducting an evaluation, psychological testing, questionnaires, behavioral observations, collateral record review, and interviews. The chapter concludes with current trends in child custody research, which include gatekeeping, relocation, child maltreatment, resist/refusal dynamics, domestic violence, attachment, and parenting plans.