Renal allograft biopsies remain the best diagnostic tool to investigate the type and degree of graft injury, provide therapeutic and prognostic information and to assess the extent of irreversible chronic organ damage - if done right. This review highlights pertinent aspects relevant not only for collecting optimal tissue samples but also for rendering diagnoses. Pathologists and clinicians are provided with "take home messages" and practical tips what to do, what to avoid and what to keep in mind.