Similar to any other investigative modality, uroflowmetry and i-UDS are very prone to show artefacts which often mimic pathological states. It is essential to understand the basic origin of these artefacts so that they can be identified and mitigated, allowing the test to be performed accurately and interpreted appropriately by effectively filtering out the deceptive findings. This chapter lists a few common artefacts which may be observed in uroflowmetry and i-UDS tracings along with the explanation about their origin and mitigation.