This paper explores the practical implications of using mixed methods for monitoring and evaluation (M&E) of international development projects, based on experiences of development researchers and practitioners. It shares lessons and insights that resulted from a three-day joint learning experience involving diverse researchers and practitioners from Wageningen Center for Development Innovation and Wageningen Economic Research, both part of Wageningen University & Research, and researchers from the Impact Measurement and Knowledge team at Oxfam Novib. The seven participating experts each contributed a case study on applying mixed methods for monitoring or evaluation, covering development projects from across the world and in a wide range of sectors and themes. The seven case studies form the basis of this paper.