This guide is intended to assist researchers, who are already familiar with formative research methods, in conducting formative assessments for infant and young child feeding programs. It offers a brief orientation to infant and young child feeding, describes major formative research methods and techniques that can be applied to nutrition, outlines a process for determining the appropriate formative research approach, and provides guidance for analyzing the information collected. The document also includes examples of formative research tools and plans and offers suggestions for analytical tools and formats.